
Ability: Sandstream
Nature: Impish
Item: Leftovers
EVs: 252 HP / 252 Def / 4 SpD
Earthquake
Ice Fang
Stealth Rock
Slack Off
Hippowdon is my physical wall for all the fighting types that fill the OU metagame. He's also able to set up Stealth Rock pretty early in the game. His sandstream works beautifully to countermine all the Politoad rain teams that dominate OU at the moment. Because he's slower, Sandstorm always kicks up after Drizzle on battle start. He has great synergy with Scizor too.
He actually works fairly well as a back up dragon killer. Since most people use Salamance or physical variants of Dragonite, Hippowdon can switch in, take a couple hits from outrage, and then proceed to break them up with Ice Fang.

Ability: Technician
Nature: Adamant
Item: Leftovers
EVs: 252 Atk /4 SpD / 252 Spe
Bug Bite
Bullet Punch
Superpower
Swords Dance
My Breaker # 1. Pretty standard set, honestly. I realize he's been played to death in the OU metagame over the years, but I had Scyther as part of my main team in Generation 1, and naturally his Gen 2 evolution kept the same spot. He's been a part of my team since day one before I'd ever heard of Smogon, and honestly I'm just thankful Scizor has held up so well all this time. obviously his moveset and the way I've used him have changed dramatically since Gen 1, but this set is so effective there's really not much to improve on at this point.

Ability: Natural Cure
Nature: Timid
Item: Expert Belt
EVs: 252 SpA / 4 SpD / 252 Spe
Surf
Ice Beam
Psychic / Thunderbolt
Rapid Spin / Recover
Ah, my old Starmie. Starmie was on my team very early on in R/B/Y, and single handedly won me the tournaments of the time. I noticed his absurd speed and special stats before I'd even finished the game for the first time. Only later on did I find out he was by far the fastest water pokemon. He's been with me ever since.
As of now, he serves as my mid-game special sweeper/rapid spinner. I very frequently change his last two move slots back and forth, depending on if I think I'll be dealing with a lot of entry hazards and/or fighting types. I've tried using Analytic over Natural Cure, but it just didn't work well, as my starmie is too frail to be switching into thing much.
Starmie is also my dragon killer, though this requires a lot of switch prediction, as he is far too frail to switch in without revenge killing.

Ability: Levitate
Nature: Calm
Item: Leftovers
EVs: 252 HP / 4 SpA / 252 SpD
Thunderbolt
Hydro Pump
Will-O-Wisp
Pain Split
Rotom-W is a brand new addition to my team. For the longest time, I used Jolteon. And while I do begrudge having a generally slower team overall without him, Rotom-W and his special defensive girth have made up for it time and time again soaking up attacks aimed at Hippowdon and Infernape. Will-O-Wisp then takes the fight out of anyone that threatens the frailer members of my team. The only real downside, aside from the trade-off in speed, is that my team now has a growing weakness to Grass.
I chose Thunderbolt over Volt Switch because Volt Switch was slowly killing him over time with Sandstorm in play, and it rarely 2HKO'd what it needed to.

Ability: Iron Fist
Nature: Naive
Item: Life Orb
EVs: 252 Atk / 4 SpA / 252 Spe
Overheat
Close Combat
Thunder Punch
Mach Punch
My late-game sweeper and counter to my team's inability to handle steel and dark types. Ever since R/B/Y, I've LOVE the concept of fire types, but never the role they ended up serving. My old Charizard was immune to earthquake, but weak to what seemed like everything else. Infernape doesn't completely solve this problem, but he's got what are in my mind, the perfect stats for what a fire-type pokemon "should" have. He's fast, he's extremely versatile on both the physical and special side, and he's got about the best move pool I've ever seen on a fire pokemon. Plus, I'll admit, I love the Chinese Zodiac/Journey To The West "wise ape" theme he's got going on.
I give him Mach Punch for priority. Thunder Punch helps very much with my team's weakness to flying types late game, as well as stave off any water type that dares to switch in.

Ability: Natural Cure
Nature: Calm
EVs: 168 SDef / 108 Spe / 232 HP
Psychic
Leaf Storm/Giga Drain
Heal Bell
Recover
My Cleric and check to my team's weakness to fighting and water types. I've found that my team gets walled and crippled fairly quickly if I don't have a way to cleanse my main wallbreakers, Scizor and Infernape of burns and poisons. Celebi fits amazingly well with my team. This slot used to be filled by the more durable Umbreon, but that left my entire team open to fighting type threats.
The 108 Speed EVs are to outspeed Breloom, which can be a pretty big threat to the rest of my team.