Well, I'm back with a new Doubles team. It occurs to me that Sunny Day got a lot of boosts with the advent of HGSS, so this team attempts to take advantage of many of these. Keep in mind that I play most of my battles in Pokémon Battle Revolution, so I'll only be picking four of these six to use in each match, and I'll be picking my leads after seeing my opponent's team. Feel free to offer suggestions for replacement team members, but I don't use any legendary Pokémon or any of the 600 BST club (Dragonite, Tyranitar, Salamence, Metagross, Garchomp). I also like to abide by Item Clause, which isn't too hard in Doubles.
Cherrim
SolarBeam
Weather Ball
Sunny Day
Protect (formerly Helping Hand)
Nature: Modest
Item: Yache Berry
Ability: Flower Gift
EVs: 244 HP, 164 SpAtk, 100 Speed
Cherrim acts primarily in a support role. Just by being on the field duing bright sun, it bestows a 1.5x multiplier to my team's Attack and SpDef stats. I believe that SolarBeam is the best choice for its primary STAB attack, being more powerful than Energy Ball and more reliable than Grass Knot. Cherrim now has access to Weather Ball as well, giving it a 100-power, sun-boosted Fire attack to throw around. The real danger with these two attacks is one of the opponents calling a different weather effect earlier in the round, causing Cherrim to waste a turn or two. There's not much I can do to avoid an opponent switching in a Hippowdon or Abomasnow, but Cherrim can use Helping Hand to aid one of my other Pokémon in swiftly taking down a potential rain user if necessary. Cherrim's Speed EVs enable it to outrun (and with bright sunlight, OHKO) Adamant, non-Scarfed Scizor.
Arcanine
Heat Wave
Crunch (formerly Dragon Pulse)
ExtremeSpeed
Morning Sun
Nature: Rash
Item: Lum Berry
Ability: Intimidate
EVs: 252 HP, 4 Attack, 132 SpAtk, 92 SpDef, 28 Speed
Arcanine's plays the role of a well-rounded Fire-type for my team. I plan to make it sturdy so that it can make use of Morning Sun effectively. My hope is that Intimidate and Flower Gift together will provide enough defensive sturdiness to allow Arcanine to take at least two hits. During sunlight, Morning Sun recovers 2/3 of Arcanine's maximum HP. Heat Wave is the standard Doubles Fire-type attack. Dragon Pulse is present primarily for Kingdra (and any other Dragon-types I run into), but it provides good coverage alongside Heat Wave. I'm considering replacing it with Crunch or the like. ExtremeSpeed is almost a must on Arcanine, and should be able to make quite a dent if boosted by Flower Gift and possibly Helping Hand. I like to put a Lum Berry on my team's best bulky attacker. Opponents that can't take it down easily tend to target it with Sleep and other nasty effects.
Aerodactyl
Rock Slide
Sky Attack
Sunny Day
Taunt
Nature: Jolly
Item: Power Herb
Ability: Pressure
EVs: 140 HP, 116 Attack, 252 Speed
An opponent's Fire-types are one of the biggest challenges that a Sunny Day team faces. Most Fire- and Grass-types just aren't equipped to effectively damage them. Aerodactyl performs mulitple roles here. First, it threatens opposing Fire-types with Rock Slide. Now, unless an opponent is double-weak to Rock, Rock Slide isn't going to OHKO it without significant support. However, it does have a 30% chance to flinch each target, giving a 51% chance to flinch at least one of the foes. I may replace it with Stone Edge after testing. Sky Attack along with Power Herb allows for a single, quick point strike. With a Flower Gift boost, there are a lot of Pokémon that can be OHKO'd by the attack. Aerodactyl is also my fastest Sunny Day user and has Taunt for general support (preventing Rain Dance, Trick Room, and the like). I have a habit of giving almost all my Pokémon HP EVs unless they have a Focus Sash, but I may decide to put those HP EVs into Attack if I end up almost OHKOing a large number of foes.
Torkoal
Heat Wave
Stone Edge
Earthquake
Sunny Day
Nature: Brave (0 Speed IVs)
Item: Heat Rock
Ability: White Smoke
EVs: 252 HP, 140 Attack, 116 SpAtk
After a lot of deliberation, I decided that Torkoal is a good fit for this team. First of all, I like to have a slow Pokémon on each team I make in order to get the jump on Trick Room teams. With Torkoal's base Speed of 20, the only fully-evolved Pokémon that 'outspeeds' it under Trick Room is Shuckle. Nothing else even ties. An opposing Trick Room Bronzong isn't going to like getting Heat Waved repeatedly. Torkoal can take quite a bit of physical punishment with its high Defense, and Cherrim's Flower Gift can supplement its SpDef if necessary. Stone Edge is my Rock-type attack here, since Torkoal has neither the typing nor the Attack stat to make Rock Slide worthwhile, even under Trick Room. I decided that at least one Pokémon on my team should have Earthquake, since half of my team resists or is immune to it. I stuck Sunny Day and a Heat Rock on, but I'm considering replacing either Earthquake or Sunny Day with Protect, since my team currently has no good way of dealing with Explosion. Curse is another possible anternative. If I get rid of Sunny Day, I'll probably replace the Heat Rock with a Sitrus Berry or Zoom Lens.
Exeggutor
Leaf Storm
Zen Headbutt
Sleep Powder
Power Swap
Nature: Rash
Item: Wide Lens
Ability: Chlorophyll
EVs: 180 HP, 116 SpDef, 212 Speed
The idea behind this set is to make good use of Power Swap. Using Leaf Storm drops Exeggutor's SpAtk by two levels. Power Swap can then give those stat drops to an opponent that uses special attacks and recharge its own SpAtk stat at the the same time. It can also swap off Attack drops from opponents' Intimidate abilities and steal the Attack and SpAtk boosts of Dragon Dance, Curse, Swords Dance, Nasty Plot, and the like. I chose Zen Headbutt over Psychic for several reasons. First, I want to be able to use my Psychic attack right after Leaf Storm without suffering a power drop. Second, Exeggutor is far more likely to have its Attack boosted than its SpAtk (through Flower Gift or stealing Attack boosts). Third, most Poison and Fighting types have higher SpDef than Defense. Sleep Powder is general utility, although the accuracy puts me off and I plan to only use it in emergencies. I may eventually replace it with Reflect, Synthesis, or something else. These EVs allow it to outspeed Pokémon with 130 base Speed once Sunny Day is in effect. Wide Lens bring Leaf Storm and Zen Headbutt's accuracy up to 99% and Sleep Powder's up to 82%.
Miltank
Body Slam
Fire Punch
Heal Bell
Milk Drink
Nature: Jolly
Item: Leftovers
Ability: Thick Fat
EVs: 196 HP, 156 Attack, 156 Speed
Miltank takes up the final slot. I wanted another Pokémon that could resist Fire and Ice. Since Water Pokémon don't have good synergy with the team and I already have two Fire Pokémon, I chose a Pokémon with Thick Fat. Miltank is actually a great fit for the group. It has a high physical Defense and Speed and Flower Gift can help make up for the mediocre Attack and SpDef. Body Slam is a favorite move of mine (with STAB, at least). The second slot currently has Fire Punch for Sunny Day synergy, but I'm also considering Punishment, Earthquake, and Wake-Up Slap. I thought I'd try Heal Bell out in the third slot, but I may eventually end up replacing it with a third attack or another support move, like Block. Milk Drink is, of course, an instant recovery move that the bulky Miltank should be able to take advantage of.
So that's the idea of the team for now. I have some big concerns. Will the team be bulky enough to actually take hits and make use of its recovery moves? Will my mixed attackers be fast and powerful enough to deal with threats, what with all the EVs in HP? Will I be able to deal with common Explosion users? Thanks for the read, and please comment if you have any ideas for the team. Am I depending too much on Cherrim? Will I be able to handle the ever-popular Rain Dance teams? You tell me!

Cherrim
SolarBeam
Weather Ball
Sunny Day
Protect (formerly Helping Hand)
Nature: Modest
Item: Yache Berry
Ability: Flower Gift
EVs: 244 HP, 164 SpAtk, 100 Speed
Cherrim acts primarily in a support role. Just by being on the field duing bright sun, it bestows a 1.5x multiplier to my team's Attack and SpDef stats. I believe that SolarBeam is the best choice for its primary STAB attack, being more powerful than Energy Ball and more reliable than Grass Knot. Cherrim now has access to Weather Ball as well, giving it a 100-power, sun-boosted Fire attack to throw around. The real danger with these two attacks is one of the opponents calling a different weather effect earlier in the round, causing Cherrim to waste a turn or two. There's not much I can do to avoid an opponent switching in a Hippowdon or Abomasnow, but Cherrim can use Helping Hand to aid one of my other Pokémon in swiftly taking down a potential rain user if necessary. Cherrim's Speed EVs enable it to outrun (and with bright sunlight, OHKO) Adamant, non-Scarfed Scizor.

Arcanine
Heat Wave
Crunch (formerly Dragon Pulse)
ExtremeSpeed
Morning Sun
Nature: Rash
Item: Lum Berry
Ability: Intimidate
EVs: 252 HP, 4 Attack, 132 SpAtk, 92 SpDef, 28 Speed
Arcanine's plays the role of a well-rounded Fire-type for my team. I plan to make it sturdy so that it can make use of Morning Sun effectively. My hope is that Intimidate and Flower Gift together will provide enough defensive sturdiness to allow Arcanine to take at least two hits. During sunlight, Morning Sun recovers 2/3 of Arcanine's maximum HP. Heat Wave is the standard Doubles Fire-type attack. Dragon Pulse is present primarily for Kingdra (and any other Dragon-types I run into), but it provides good coverage alongside Heat Wave. I'm considering replacing it with Crunch or the like. ExtremeSpeed is almost a must on Arcanine, and should be able to make quite a dent if boosted by Flower Gift and possibly Helping Hand. I like to put a Lum Berry on my team's best bulky attacker. Opponents that can't take it down easily tend to target it with Sleep and other nasty effects.

Aerodactyl
Rock Slide
Sky Attack
Sunny Day
Taunt
Nature: Jolly
Item: Power Herb
Ability: Pressure
EVs: 140 HP, 116 Attack, 252 Speed
An opponent's Fire-types are one of the biggest challenges that a Sunny Day team faces. Most Fire- and Grass-types just aren't equipped to effectively damage them. Aerodactyl performs mulitple roles here. First, it threatens opposing Fire-types with Rock Slide. Now, unless an opponent is double-weak to Rock, Rock Slide isn't going to OHKO it without significant support. However, it does have a 30% chance to flinch each target, giving a 51% chance to flinch at least one of the foes. I may replace it with Stone Edge after testing. Sky Attack along with Power Herb allows for a single, quick point strike. With a Flower Gift boost, there are a lot of Pokémon that can be OHKO'd by the attack. Aerodactyl is also my fastest Sunny Day user and has Taunt for general support (preventing Rain Dance, Trick Room, and the like). I have a habit of giving almost all my Pokémon HP EVs unless they have a Focus Sash, but I may decide to put those HP EVs into Attack if I end up almost OHKOing a large number of foes.

Torkoal
Heat Wave
Stone Edge
Earthquake
Sunny Day
Nature: Brave (0 Speed IVs)
Item: Heat Rock
Ability: White Smoke
EVs: 252 HP, 140 Attack, 116 SpAtk
After a lot of deliberation, I decided that Torkoal is a good fit for this team. First of all, I like to have a slow Pokémon on each team I make in order to get the jump on Trick Room teams. With Torkoal's base Speed of 20, the only fully-evolved Pokémon that 'outspeeds' it under Trick Room is Shuckle. Nothing else even ties. An opposing Trick Room Bronzong isn't going to like getting Heat Waved repeatedly. Torkoal can take quite a bit of physical punishment with its high Defense, and Cherrim's Flower Gift can supplement its SpDef if necessary. Stone Edge is my Rock-type attack here, since Torkoal has neither the typing nor the Attack stat to make Rock Slide worthwhile, even under Trick Room. I decided that at least one Pokémon on my team should have Earthquake, since half of my team resists or is immune to it. I stuck Sunny Day and a Heat Rock on, but I'm considering replacing either Earthquake or Sunny Day with Protect, since my team currently has no good way of dealing with Explosion. Curse is another possible anternative. If I get rid of Sunny Day, I'll probably replace the Heat Rock with a Sitrus Berry or Zoom Lens.

Exeggutor
Leaf Storm
Zen Headbutt
Sleep Powder
Power Swap
Nature: Rash
Item: Wide Lens
Ability: Chlorophyll
EVs: 180 HP, 116 SpDef, 212 Speed
The idea behind this set is to make good use of Power Swap. Using Leaf Storm drops Exeggutor's SpAtk by two levels. Power Swap can then give those stat drops to an opponent that uses special attacks and recharge its own SpAtk stat at the the same time. It can also swap off Attack drops from opponents' Intimidate abilities and steal the Attack and SpAtk boosts of Dragon Dance, Curse, Swords Dance, Nasty Plot, and the like. I chose Zen Headbutt over Psychic for several reasons. First, I want to be able to use my Psychic attack right after Leaf Storm without suffering a power drop. Second, Exeggutor is far more likely to have its Attack boosted than its SpAtk (through Flower Gift or stealing Attack boosts). Third, most Poison and Fighting types have higher SpDef than Defense. Sleep Powder is general utility, although the accuracy puts me off and I plan to only use it in emergencies. I may eventually replace it with Reflect, Synthesis, or something else. These EVs allow it to outspeed Pokémon with 130 base Speed once Sunny Day is in effect. Wide Lens bring Leaf Storm and Zen Headbutt's accuracy up to 99% and Sleep Powder's up to 82%.

Miltank
Body Slam
Fire Punch
Heal Bell
Milk Drink
Nature: Jolly
Item: Leftovers
Ability: Thick Fat
EVs: 196 HP, 156 Attack, 156 Speed
Miltank takes up the final slot. I wanted another Pokémon that could resist Fire and Ice. Since Water Pokémon don't have good synergy with the team and I already have two Fire Pokémon, I chose a Pokémon with Thick Fat. Miltank is actually a great fit for the group. It has a high physical Defense and Speed and Flower Gift can help make up for the mediocre Attack and SpDef. Body Slam is a favorite move of mine (with STAB, at least). The second slot currently has Fire Punch for Sunny Day synergy, but I'm also considering Punishment, Earthquake, and Wake-Up Slap. I thought I'd try Heal Bell out in the third slot, but I may eventually end up replacing it with a third attack or another support move, like Block. Milk Drink is, of course, an instant recovery move that the bulky Miltank should be able to take advantage of.
So that's the idea of the team for now. I have some big concerns. Will the team be bulky enough to actually take hits and make use of its recovery moves? Will my mixed attackers be fast and powerful enough to deal with threats, what with all the EVs in HP? Will I be able to deal with common Explosion users? Thanks for the read, and please comment if you have any ideas for the team. Am I depending too much on Cherrim? Will I be able to handle the ever-popular Rain Dance teams? You tell me!