In Brawl, I'm the guy who wins. It feels good to see my second-best-Brawler-friend claim that KOs make the winner, not number of falls, and that the current method for determining the winner is bullshit.
In TF2, I'm utility. Whatever they need. If no one needs anything in particular, I go Pyro or Soldier. I am the world's worst Spy, Scout, and Demoman. World's second worst Sniper. My Pyro playstyle is strangely defensive in Capture the Flag/Payload, however. Sure, we lose an attacker, but no Spies get through and I ambush people trying to flank.
I rarely play a standard online FPS with friends, but I usually take an accurate assault rifle with a good scope and pretend I'm a sniper. More effective than you think.
Back in my StarCraft days I was known for being the Zerg player that never rushed. Oh, and hydralisks. Millions of hydralisks and a bunch of guardians. For the Swarm, baby.