If anyone guesses where I got that name from, they get a cookie. This is a team that I devised a few months back and now I have edited it. Not necessarily that my old team didn't work, its just that I was bored (and I wanted to update it to Platinum). Anyways, the stars of the show:
Mewtwo @ Choice Specs
Timid Nature - Pressure
EVs: 42 HP / 252 SpA / 216 Spe
-Aura Sphere
-Flamethrower
-Grass Knot
-Ice Beam
Hits hard and a great way to start off my team. Aura Sphere and Ice Beam are pretty standard and Flamethrower is for things like lead Metagross and Grass Knot is because I lack Grass moves in general on this team. Gives my team a better offensive presence overall as it hits hard and fast with no set-up.
Latias @ Soul Dew
Timid Nature - Levitate
EVs: 112 HP / 204 SpA /192 Spe
-Calm Mind
-Recover
-Dragon Pulse
-Thunder
My Calm Minder on the team and the main Kyogre counter. Electric attacks have generally better coverage than Grass types, and I can take care of Groudon with Lugia anyways. So Thunder it is.
Blissey @ Leftovers
Calm Nature - Natural Cure
EVs: 6 HP / 252 Def / 252 SpD
-Ice Beam
-Seismic Toss
-Thunder Wave
-Softboiled
Walls specially. The EVs in defense give me some leeway in predicting moves. Ice Beam and Seismic Toss together allow me to do some damage to every pokemon.
Lugia @ Leftovers
Bold Nature - Pressure
EVs: 252 HP / 52 Def / 204 Spe
-Roost
-Reflect
-Whirlwind
-Ice Beam
Walls on the physical side. Ice Beam is there because it has fairly good coverage and I already have Blissey statusing things. Reflect and Whirlwind are good support options. I am using this mainly over Giratina because I think that Giratina has more common Uber weaknesses (not to say that Lugia doesn't, Lugia just has less).
Dialga @ Expert Belt
Quiet Nature - Pressure
EVs: 120 HP / 136 Atk / 252 SpA
-Thunder
-Draco Meteor
-Fire Blast
-Brick Break
Wall breaker. Welcomes Paralysis support from Miss Bliss and is on this team mainly to take out Blissey and other annoying walls like Giratina and Lugia. I prefer Fire Blast on this set as I really want to be able to take on things like Metagross if need be. Expert Belt over Life Orb as I am pretty slow and need to be able to take some hits. Helps take the walls out that stop my main sweeper.
Rayquaza@ Life Orb
Jolly Nature - Air Lock
EVs: 40 Hp / 216 Atk / 252 Spd
- Swords Dance
- Dragon Claw
- Extreme Speed
- Waterfall
The main sweeper! Swords Dances on anything stuck on a resisted move or that fears me and I sweep away. Dragon Claw for STAB goodness, Extremespeed for fast and frail sweepers then Waterfall for type coverage on everything else. However, as amazing as Rayquaza can be, I am thinking that I may want something like a Choice Band Metagross here to revenge kill for my team.
So Smogon, what are your thoughts?

Mewtwo @ Choice Specs
Timid Nature - Pressure
EVs: 42 HP / 252 SpA / 216 Spe
-Aura Sphere
-Flamethrower
-Grass Knot
-Ice Beam
Hits hard and a great way to start off my team. Aura Sphere and Ice Beam are pretty standard and Flamethrower is for things like lead Metagross and Grass Knot is because I lack Grass moves in general on this team. Gives my team a better offensive presence overall as it hits hard and fast with no set-up.

Latias @ Soul Dew
Timid Nature - Levitate
EVs: 112 HP / 204 SpA /192 Spe
-Calm Mind
-Recover
-Dragon Pulse
-Thunder
My Calm Minder on the team and the main Kyogre counter. Electric attacks have generally better coverage than Grass types, and I can take care of Groudon with Lugia anyways. So Thunder it is.

Blissey @ Leftovers
Calm Nature - Natural Cure
EVs: 6 HP / 252 Def / 252 SpD
-Ice Beam
-Seismic Toss
-Thunder Wave
-Softboiled
Walls specially. The EVs in defense give me some leeway in predicting moves. Ice Beam and Seismic Toss together allow me to do some damage to every pokemon.

Lugia @ Leftovers
Bold Nature - Pressure
EVs: 252 HP / 52 Def / 204 Spe
-Roost
-Reflect
-Whirlwind
-Ice Beam
Walls on the physical side. Ice Beam is there because it has fairly good coverage and I already have Blissey statusing things. Reflect and Whirlwind are good support options. I am using this mainly over Giratina because I think that Giratina has more common Uber weaknesses (not to say that Lugia doesn't, Lugia just has less).

Dialga @ Expert Belt
Quiet Nature - Pressure
EVs: 120 HP / 136 Atk / 252 SpA
-Thunder
-Draco Meteor
-Fire Blast
-Brick Break
Wall breaker. Welcomes Paralysis support from Miss Bliss and is on this team mainly to take out Blissey and other annoying walls like Giratina and Lugia. I prefer Fire Blast on this set as I really want to be able to take on things like Metagross if need be. Expert Belt over Life Orb as I am pretty slow and need to be able to take some hits. Helps take the walls out that stop my main sweeper.

Rayquaza@ Life Orb
Jolly Nature - Air Lock
EVs: 40 Hp / 216 Atk / 252 Spd
- Swords Dance
- Dragon Claw
- Extreme Speed
- Waterfall
The main sweeper! Swords Dances on anything stuck on a resisted move or that fears me and I sweep away. Dragon Claw for STAB goodness, Extremespeed for fast and frail sweepers then Waterfall for type coverage on everything else. However, as amazing as Rayquaza can be, I am thinking that I may want something like a Choice Band Metagross here to revenge kill for my team.
So Smogon, what are your thoughts?