My first and only team at the moment, this team has changed heavily since when I first created it due to many battles and experience. This final result plays very well and can counter nearly every OU pokemon, barring a few (such as some Latias and Lucario variants, but I usually do well).
I have a switch in for every status-inducing move, as well as immunities to Normal, Fighting, Ground, Poison, Fire, Water, and Electric.
Froslass @ Choice Scarf
Ability: Snow Cloak
Timid , 252 HP / 252 Speed / 4 SpA
-Shadow Ball
-Spikes
-Trick
-Destiny Bond
This lead I adapted from Metagross's trick set and Froslass's lead set, and effectively functions both as a lead and an anti-lead, as well as an anti-anti-lead, being immune to fake out. Not too sure on the EV's, though. The deal here is to trick the choice scarf onto the lead while they use stealth rock or something. As they switch I get a layer of spikes up. Taunt is a little more annoying because even though they are forced to switch, I can't get spikes up. But neither do they.
The reason I chose Shadow Ball over Ice Beam is because it works better against opposing Azelf and Metagross, which are extremely common, whereas Aerodactyl is not. I nearly always get at least one layer of spikes down while incapacitating their lead, and it is always a good feeling to watch opposing Tyranitars and Salamences fall in one hit to Destiny Bond. Another good thing is I often get a Focus Sash from the opposing lead, guaranteeing another layer of spikes at 1 HP before Destiny Bonding.
Although this Froslass has both its types shared by other members of my team, being a suicide lead this is made up for as he doesn't stick around long. In fact, he rarely, if ever, will switch until it is dead, unless taunted.
This Froslass is so amazing, I only just now noticed he was accidentally running 252 Attack EV's, and was still awesome!
Weaknesses:
Being a suicide lead this is not as important.
Rotom-S @ Choice Specs
Ability: Levitate
Timid, 252 SpA / 252 Speed / 6 SpD
-Thunderbolt
-Trick
-Shadow Ball
-Air Slash
While Fan Rotom rarely sees daylight these days, it works extremely well and will effectively counter Machamp and Heracross. Trick incapacitates so many of Rotom's switch-ins and will stop Suicune from Stalling my Vaporeon. Suicunes really hate Choice Specs, but Rotom doesn't mind Leftovers.
While Fan Rotom faces serious competition on this team with Mow Rotom, especially being as I lack a Grass move (this is only a problem against Quagsire, who never sees any use), but in the end I decided that I needed Air Slash to prevent Heracross from ruining my day, and Machamps and Brelooms are scared off by it too.
Weaknesses:
Ghost-Heatran
Dark- Heatran, Heracross
Heatran @ Leftovers
Ability: Flash Fire
Modest, 248 HP / 56 SpA / 204 SpD
-Lava Plume
-Sleep Talk
-Earth Power
-Rest
This member has changed more than anyone else on the team. Originally starting as a cleric Celebi, then changing to a Scarf Heatran, than a Torment Tran, finally arriving at this RestTalk variant. The reason I chose the Rest Talk set is so I could finally have a switch-in to every status move, whereas before sleeping moves were killing me. This Heatran can switch into Toxic without a scratch, Will-O-Wisp while getting a Fire boost, and now Sleep Powder and Spore to fight back with Sleep Talk. Thunder Wave is resisted by Mamoswine.
Weaknesses:
Ground - Rotom-S, Heracross
Water - Vaporeon
Vaporeon @ Leftovers
Ability: Water Absorb
Bold, 252 Def / 188 HP / 68 Speed
-Wish
-Hidden Power Electric
-Surf
-Protect
One of my favorite pokemon, this guy can stall out almost anything, and I've never seen it OHKO'd, even by a Draco Meteor from Latias. It counter Gyarados extremely well, often OHKOing with Hidden Power. All Gyarados can do to me is Earthquake, which usually takes 3 hits to KO me. It owns the Bounce variants with Protect, and can come in on Waterfall and heal off Stealth Rock's damage. Vaporeon effectively walls Swampert, Surf does a surprising amount of damage to it despite being neutral. This thing is walled to High Heaven by Crocunes, who will PP stall it to death despite not being able to damage it. This is fixed by tricking Choice Specs onto them via Rotom (I love tricking Crocunes, there is almost nothing as satisfying). Vaporeon can safely come in on Fire and Water attacks, which are very easy to predict.
Weaknesses:
Electric- Rotom, Mamoswine
Grass - Heatran, Heracross
Mamoswine @ Leftovers
Ability: Snow Cloak
Adamant, 176 HP / 116 Atk / 20 SpD / 196 Speed
-Toxic
-Stealth Rock
-Earthquake
-Ice Shard
For the longest time this was a Curse set, but I think this works better being as I don't have any other status moves or Stealth Rock, while still retaining the awesomeness of Ice Shard. Mamoswine is one of the few pokemon who can counter the infamous Flinch Togekiss, being immune to Thunder Wave and hitting back with Stabbed Supereffective Ice Shard and going first at the same time. Aura Sphere will rarely, if ever, OHKO, and Ice Shard moves before Roost, so I always win. This pokemon counters the beasts that are Gliscor, Flygon, Salamence, and Dragonite (though ExtreemeSpeed is problematic), always one-or-two-hit KO'ing, even after Intimidate unless Salamence invests in Defense or HP like Fatmence, which still isn't much of a problem. The Immunity to Electric is extremely useful alongside my Vaporeon, which can't stand Paralysis. This set also counters Jolteon, Electivire, and others.
Weaknesses:
Fire - Heatran, Vaporeon
Water - Vaporeon
Grass - Heatran, Heracross
Fighting - Rotom, Heracross
Steel - Rotom, Heatran, Vaporeon
Heracross @ Choice Scarf
Ability: Guts
Adamant, 252 Atk / 252 Speed / 6 Def
-Close Combat
-Megahorn
-Stone Edge
-Pursuit
And here arrives the rest of my type coverage. This was a Band variant for a very long time, but was extremely ineffective, and when I switched to Scarf it was such a drastic change it was incredible. The Scarf Heracross can now sweep almost everything in existence. Close Combat is absolutely deadly, OHKOing Tyranitar, Blissey, Weavile and so many others no matter what they do. Megahorn has accuracy issues, and so does Stone Edge, which I rarely use but can't live without. Pursuit replaces Night Slash and works better IMO, especially for taking out half of Blissey's health as she switches (and often to a Ghost-type, expecting Close Combat, which in turn causes even more problems for the poor opponent). This Heracross counters Blissey to kingdom come, able to soak up Toxic and get a Guts boost, effectively giving the effect of both a Choice Band and Choice Scarf. Flamethrower is only a problem if I am dumb enough to switch into it.
Weaknesses:
Fire - Heatran, Vaporeon
Flying - Heatran, Rotom
Psychic - Heatran
I have a switch in for every status-inducing move, as well as immunities to Normal, Fighting, Ground, Poison, Fire, Water, and Electric.

Froslass @ Choice Scarf
Ability: Snow Cloak
Timid , 252 HP / 252 Speed / 4 SpA
-Shadow Ball
-Spikes
-Trick
-Destiny Bond
This lead I adapted from Metagross's trick set and Froslass's lead set, and effectively functions both as a lead and an anti-lead, as well as an anti-anti-lead, being immune to fake out. Not too sure on the EV's, though. The deal here is to trick the choice scarf onto the lead while they use stealth rock or something. As they switch I get a layer of spikes up. Taunt is a little more annoying because even though they are forced to switch, I can't get spikes up. But neither do they.
The reason I chose Shadow Ball over Ice Beam is because it works better against opposing Azelf and Metagross, which are extremely common, whereas Aerodactyl is not. I nearly always get at least one layer of spikes down while incapacitating their lead, and it is always a good feeling to watch opposing Tyranitars and Salamences fall in one hit to Destiny Bond. Another good thing is I often get a Focus Sash from the opposing lead, guaranteeing another layer of spikes at 1 HP before Destiny Bonding.
Although this Froslass has both its types shared by other members of my team, being a suicide lead this is made up for as he doesn't stick around long. In fact, he rarely, if ever, will switch until it is dead, unless taunted.
This Froslass is so amazing, I only just now noticed he was accidentally running 252 Attack EV's, and was still awesome!
Weaknesses:
Being a suicide lead this is not as important.

Rotom-S @ Choice Specs
Ability: Levitate
Timid, 252 SpA / 252 Speed / 6 SpD
-Thunderbolt
-Trick
-Shadow Ball
-Air Slash
While Fan Rotom rarely sees daylight these days, it works extremely well and will effectively counter Machamp and Heracross. Trick incapacitates so many of Rotom's switch-ins and will stop Suicune from Stalling my Vaporeon. Suicunes really hate Choice Specs, but Rotom doesn't mind Leftovers.
While Fan Rotom faces serious competition on this team with Mow Rotom, especially being as I lack a Grass move (this is only a problem against Quagsire, who never sees any use), but in the end I decided that I needed Air Slash to prevent Heracross from ruining my day, and Machamps and Brelooms are scared off by it too.
Weaknesses:
Ghost-Heatran
Dark- Heatran, Heracross

Heatran @ Leftovers
Ability: Flash Fire
Modest, 248 HP / 56 SpA / 204 SpD
-Lava Plume
-Sleep Talk
-Earth Power
-Rest
This member has changed more than anyone else on the team. Originally starting as a cleric Celebi, then changing to a Scarf Heatran, than a Torment Tran, finally arriving at this RestTalk variant. The reason I chose the Rest Talk set is so I could finally have a switch-in to every status move, whereas before sleeping moves were killing me. This Heatran can switch into Toxic without a scratch, Will-O-Wisp while getting a Fire boost, and now Sleep Powder and Spore to fight back with Sleep Talk. Thunder Wave is resisted by Mamoswine.
Weaknesses:
Ground - Rotom-S, Heracross
Water - Vaporeon

Vaporeon @ Leftovers
Ability: Water Absorb
Bold, 252 Def / 188 HP / 68 Speed
-Wish
-Hidden Power Electric
-Surf
-Protect
One of my favorite pokemon, this guy can stall out almost anything, and I've never seen it OHKO'd, even by a Draco Meteor from Latias. It counter Gyarados extremely well, often OHKOing with Hidden Power. All Gyarados can do to me is Earthquake, which usually takes 3 hits to KO me. It owns the Bounce variants with Protect, and can come in on Waterfall and heal off Stealth Rock's damage. Vaporeon effectively walls Swampert, Surf does a surprising amount of damage to it despite being neutral. This thing is walled to High Heaven by Crocunes, who will PP stall it to death despite not being able to damage it. This is fixed by tricking Choice Specs onto them via Rotom (I love tricking Crocunes, there is almost nothing as satisfying). Vaporeon can safely come in on Fire and Water attacks, which are very easy to predict.
Weaknesses:
Electric- Rotom, Mamoswine
Grass - Heatran, Heracross

Mamoswine @ Leftovers
Ability: Snow Cloak
Adamant, 176 HP / 116 Atk / 20 SpD / 196 Speed
-Toxic
-Stealth Rock
-Earthquake
-Ice Shard
For the longest time this was a Curse set, but I think this works better being as I don't have any other status moves or Stealth Rock, while still retaining the awesomeness of Ice Shard. Mamoswine is one of the few pokemon who can counter the infamous Flinch Togekiss, being immune to Thunder Wave and hitting back with Stabbed Supereffective Ice Shard and going first at the same time. Aura Sphere will rarely, if ever, OHKO, and Ice Shard moves before Roost, so I always win. This pokemon counters the beasts that are Gliscor, Flygon, Salamence, and Dragonite (though ExtreemeSpeed is problematic), always one-or-two-hit KO'ing, even after Intimidate unless Salamence invests in Defense or HP like Fatmence, which still isn't much of a problem. The Immunity to Electric is extremely useful alongside my Vaporeon, which can't stand Paralysis. This set also counters Jolteon, Electivire, and others.
Weaknesses:
Fire - Heatran, Vaporeon
Water - Vaporeon
Grass - Heatran, Heracross
Fighting - Rotom, Heracross
Steel - Rotom, Heatran, Vaporeon

Heracross @ Choice Scarf
Ability: Guts
Adamant, 252 Atk / 252 Speed / 6 Def
-Close Combat
-Megahorn
-Stone Edge
-Pursuit
And here arrives the rest of my type coverage. This was a Band variant for a very long time, but was extremely ineffective, and when I switched to Scarf it was such a drastic change it was incredible. The Scarf Heracross can now sweep almost everything in existence. Close Combat is absolutely deadly, OHKOing Tyranitar, Blissey, Weavile and so many others no matter what they do. Megahorn has accuracy issues, and so does Stone Edge, which I rarely use but can't live without. Pursuit replaces Night Slash and works better IMO, especially for taking out half of Blissey's health as she switches (and often to a Ghost-type, expecting Close Combat, which in turn causes even more problems for the poor opponent). This Heracross counters Blissey to kingdom come, able to soak up Toxic and get a Guts boost, effectively giving the effect of both a Choice Band and Choice Scarf. Flamethrower is only a problem if I am dumb enough to switch into it.
Weaknesses:
Fire - Heatran, Vaporeon
Flying - Heatran, Rotom
Psychic - Heatran