This is the team I have been using for a few days. It has been doing pretty well and honestly it is probably my "Best Team for Platinum". Although it is pretty good I know that there is of course room for improvement. So I am posting this team to get that improvement. So uhhh... Por favor, tasa de.
Swampert (M) @ Leftovers
Ability: Torrent
EVs: 240 HP/216 Def/52 SAtk
Relaxed nature (+Def, -Spd)
- Earthquake
- Ice Beam
- Protect
- Stealth Rock
Alright this is pretty much an anti lead. Looking at the Top leads you have something like: Tyranitar, Heatran, Metagross and Infernape. This swampert beats every single one of them. Though it takes a bit of prediction. First of all I usually EQ. Heatran, Metagross and Infernape almost always Stealth Rock first and when I EQ they want to take Swampert out since Swampert is a general pain in the but for any team to handle. So I almost always protect on Turn 2. After that I have a Swampert at 100% ready to take on a dragon or if they mispredict two. You may notice that with my plan I don't Stealth Rock. Well sometimes I do Stealth Rock. Especially against something that can't touch me like Tyranitar. Protect is also nifty for Leftovers gain. Earthquake+Ice Beam gets pretty much perfect coverage in OU and pretty much is all Swampert needs to counter what it needs to counter.
---
Jirachi @ Expert Belt
Ability: Serene Grace
EVs: 252 Atk/252 Spd/4 SAtk
Hasty nature (+Spd, -Def)
- Iron Head
- Ice Punch
- Fire Punch
- Grass Knot
This is a beautiful wall breaker made by TAY. It usually gives the oponent the impression that it is scarfed which usually nabs it more than one kill per game. Iron Head is nice for the chance of flinching while Ice Punch and Fire Punch give me pretty nice coverage. Grass Knot tears apart stuff like Suicune and Swampert. I usually try to keep this away from stuff like Heatran and Gyarados though since it struggles to do much damage to both... even though Celebi and Infernape hit Gyarados like a nuke with Grass Knot. This is my only steel type meaning that most of the time this is switching into Salamence after it has used Outrage and killed something. Fire Punch does fend off Magnezone for a bit since most people don't like for it to take much damage...if any. This guy has saved me and was the pokemon for which this team was built around.
---
Tyranitar (M) @ Choice Band
Ability: Sand Stream
EVs: 252 HP/40 Atk/216 SDef
Careful nature (+SDef, -SAtk)
- Crunch
- Stone Edge
- Earthquake
- Pursuit
This guy comes in on stuff like HP Grass Zapdos and laughs basically. Crunch is for some nice STAB action and puts Gengar and friends in their grave. Stone Edge is for flying types and EQ is for just about anything else. This is Blissey switchin #2. I usually let Machamp take care of Blissey though since he is more suited for the job. Pursuit catches fleeing pixies and eats them up (I'm looking at you Azelf and Celebi). This was originally a BabiriTar but I found my self to be incredibly Heatran weak since Swampert couldn't take repeated beatings and it's not like Latias likes the possiblity of being hit with a Dragon Pulse. So I added this guy to the team and honestly this has been 10000 times better in terms of bulk. Machamp hates Psychic types and this guy just laughs at them.
---
Rotom-h @ Leftovers
Ability: Levitate
EVs: 252 HP/168 Def/88 Spd
Bold nature (+Def, -Atk)
- Thunderbolt
- Shadow Ball/Light Screen
- Overheat
- Will-o-wisp
Ok this is my Spin Blocker since I like to build up residual damage though he wasn't really put there for spin blocking. He was put there for the ability to counter Mamoswine as well as Lucario+Scizor. Will o Wisp cripples most of his switch ins and helps build up residual damage. Overheat just straight out frys Scizor while Shadow Ball is helpful against Psychic types like Latias. Oh and just for more fun... he counters Gyarados which means more fun for Jirachi :). This guy usually attracts Heatran which means a free switchin for Tyranitar and Swampert. Considering Light Screen just because I feel I have enough physical bulk on this team that I can counter most of the threats in the metagame. This guy also hates when Tyranitar switches in on him which makes Machamp and Swampert very effective at switching in :).
---
Machamp (M) @ Leftovers
Ability: No Guard
EVs: 108 HP/144 Atk/252 Def/4 Spd
Impish nature (+Def, -SAtk)
- Rest
- Sleep Talk
- Dynamic Punch
- Stone Edge
Yes yes yes...get it all out. Laugh all you want but be warned this is a truly dangerous set when played correctly. Most people look at Low Kick and laugh but thanks to a heavy metagame such as OU... and a status filled one at that this set really does do a lot of damage. Machamp is my primary status absorber. Taking any status happily and attacking with boosted attacks and rock solid defenses (and abs :naughty:). Stone Edge covers any flying types that want to switch in to me. I found the standard EVs to be so weak that I actually scrolled down to the EV's section and found this spread which is more acclimated towards countering Tyranitar and ect. And of course Rest+Sleep Talk allows him to have Recover and attack. Blissey counter #1.
Gave him No Guard and Dynamic Punch.
---
Latias (F) @ Leftovers
Ability: Levitate
EVs: 148 HP/252 Spd/108 SAtk
Timid nature (+Spd, -Atk)
- Calm Mind
- Dragon Pulse
- Surf
- Recover
And finally my late game cleanerupper. Calm Mind on stuff like Celebi and start attacking with either of the two moves. Dragon Pulse gets coverage on everything except steel types which are hit hard by Surf. Obviously HP Fire would give me an unresisted combo but it would leave me to do jackshit to Tyranitar. I wanted to use Wish on this to support Swampert but I found it to be an inferior sweeper. Recover is for recovery. I am just a fan of bulky pokemon which is why I didn't use the offensive spread. Infernape counter as well which I needed desperately.
---
Well that's all! Rate, Comment, Steal. Thanks to Blue Ace for the pics.

Swampert (M) @ Leftovers
Ability: Torrent
EVs: 240 HP/216 Def/52 SAtk
Relaxed nature (+Def, -Spd)
- Earthquake
- Ice Beam
- Protect
- Stealth Rock
Alright this is pretty much an anti lead. Looking at the Top leads you have something like: Tyranitar, Heatran, Metagross and Infernape. This swampert beats every single one of them. Though it takes a bit of prediction. First of all I usually EQ. Heatran, Metagross and Infernape almost always Stealth Rock first and when I EQ they want to take Swampert out since Swampert is a general pain in the but for any team to handle. So I almost always protect on Turn 2. After that I have a Swampert at 100% ready to take on a dragon or if they mispredict two. You may notice that with my plan I don't Stealth Rock. Well sometimes I do Stealth Rock. Especially against something that can't touch me like Tyranitar. Protect is also nifty for Leftovers gain. Earthquake+Ice Beam gets pretty much perfect coverage in OU and pretty much is all Swampert needs to counter what it needs to counter.
---

Jirachi @ Expert Belt
Ability: Serene Grace
EVs: 252 Atk/252 Spd/4 SAtk
Hasty nature (+Spd, -Def)
- Iron Head
- Ice Punch
- Fire Punch
- Grass Knot
This is a beautiful wall breaker made by TAY. It usually gives the oponent the impression that it is scarfed which usually nabs it more than one kill per game. Iron Head is nice for the chance of flinching while Ice Punch and Fire Punch give me pretty nice coverage. Grass Knot tears apart stuff like Suicune and Swampert. I usually try to keep this away from stuff like Heatran and Gyarados though since it struggles to do much damage to both... even though Celebi and Infernape hit Gyarados like a nuke with Grass Knot. This is my only steel type meaning that most of the time this is switching into Salamence after it has used Outrage and killed something. Fire Punch does fend off Magnezone for a bit since most people don't like for it to take much damage...if any. This guy has saved me and was the pokemon for which this team was built around.
---

Tyranitar (M) @ Choice Band
Ability: Sand Stream
EVs: 252 HP/40 Atk/216 SDef
Careful nature (+SDef, -SAtk)
- Crunch
- Stone Edge
- Earthquake
- Pursuit
This guy comes in on stuff like HP Grass Zapdos and laughs basically. Crunch is for some nice STAB action and puts Gengar and friends in their grave. Stone Edge is for flying types and EQ is for just about anything else. This is Blissey switchin #2. I usually let Machamp take care of Blissey though since he is more suited for the job. Pursuit catches fleeing pixies and eats them up (I'm looking at you Azelf and Celebi). This was originally a BabiriTar but I found my self to be incredibly Heatran weak since Swampert couldn't take repeated beatings and it's not like Latias likes the possiblity of being hit with a Dragon Pulse. So I added this guy to the team and honestly this has been 10000 times better in terms of bulk. Machamp hates Psychic types and this guy just laughs at them.
---

Rotom-h @ Leftovers
Ability: Levitate
EVs: 252 HP/168 Def/88 Spd
Bold nature (+Def, -Atk)
- Thunderbolt
- Shadow Ball/Light Screen
- Overheat
- Will-o-wisp
Ok this is my Spin Blocker since I like to build up residual damage though he wasn't really put there for spin blocking. He was put there for the ability to counter Mamoswine as well as Lucario+Scizor. Will o Wisp cripples most of his switch ins and helps build up residual damage. Overheat just straight out frys Scizor while Shadow Ball is helpful against Psychic types like Latias. Oh and just for more fun... he counters Gyarados which means more fun for Jirachi :). This guy usually attracts Heatran which means a free switchin for Tyranitar and Swampert. Considering Light Screen just because I feel I have enough physical bulk on this team that I can counter most of the threats in the metagame. This guy also hates when Tyranitar switches in on him which makes Machamp and Swampert very effective at switching in :).
---

Machamp (M) @ Leftovers
Ability: No Guard
EVs: 108 HP/144 Atk/252 Def/4 Spd
Impish nature (+Def, -SAtk)
- Rest
- Sleep Talk
- Dynamic Punch
- Stone Edge
Yes yes yes...get it all out. Laugh all you want but be warned this is a truly dangerous set when played correctly. Most people look at Low Kick and laugh but thanks to a heavy metagame such as OU... and a status filled one at that this set really does do a lot of damage. Machamp is my primary status absorber. Taking any status happily and attacking with boosted attacks and rock solid defenses (and abs :naughty:). Stone Edge covers any flying types that want to switch in to me. I found the standard EVs to be so weak that I actually scrolled down to the EV's section and found this spread which is more acclimated towards countering Tyranitar and ect. And of course Rest+Sleep Talk allows him to have Recover and attack. Blissey counter #1.
Gave him No Guard and Dynamic Punch.
---

Latias (F) @ Leftovers
Ability: Levitate
EVs: 148 HP/252 Spd/108 SAtk
Timid nature (+Spd, -Atk)
- Calm Mind
- Dragon Pulse
- Surf
- Recover
And finally my late game cleanerupper. Calm Mind on stuff like Celebi and start attacking with either of the two moves. Dragon Pulse gets coverage on everything except steel types which are hit hard by Surf. Obviously HP Fire would give me an unresisted combo but it would leave me to do jackshit to Tyranitar. I wanted to use Wish on this to support Swampert but I found it to be an inferior sweeper. Recover is for recovery. I am just a fan of bulky pokemon which is why I didn't use the offensive spread. Infernape counter as well which I needed desperately.
---
Well that's all! Rate, Comment, Steal. Thanks to Blue Ace for the pics.