Well I'm generally good at shooters. Currently playing Medal of Honor online and I'm usually in the top 2 of my team. But I kick ass in Gears of war, Halo, Cod, and we still lan a little counter strike every now and then.
Only fighter I'm really good at is Tekken and I Guess street fighter 4. I cant really test out my sf skills because all my friends prefer Tekken.
Sports games. Mainly FIFA, Rugby and Fight Night. And I'm decent in most RTS's. Pretty good at company of Heroes.
As for RPG's... wouldn't consider myself really good. But I still love'em!
Last but certainly not least. Dirt 1 and 2. The only racing games I play because I gave up on all the others. But I kick ass with Dirt!