I'm not exceptional at any game in particular, but what I do have is a very particular set of skills across a broad range of games. I'm exceptionally great at racing, shooters, horror, micromanaging, RTS, God games, RPG's, the lot.
There are only 3 types of games I'm not ridiculously good at, and that's:
[li]MMO's (I'm average)[/li]
[li]Fighting game (I'm crap at)[/li]
[li]Platformers (including Mario and donkey Kong)[/li]
Apart from that I can usually beat a game in its hardest difficulty. If it's multiplayer, I pull my weight into a near 1.9 Kill-Death and Win-Loss ratio per match, and can even carry a team of deadweights into a victory against the above-average players in some games. Sometimes if I notice I'm stealing glory out from under a team-mates fingertips (kill stealing, unintentional resource greed, weapon hogging, etc.) I'll hold back and let them pick up a few points too, because it's not fun if nobody else is having fun.
I only struggle to beat individuals or teams who dedicate all their gaming to that particular game; for arguments sake, those 3.0 KD, 4000 games-played Halo MLG wannabe's who seem persistent to play slayer in objective playlists. I don't even play immorally, hell, I might stop playing multiplayer games on Sundays as it seems to be the day all the inept and immoral people play online games.