Shooters, I guess. The thing is, on the one hand, I don't think I'm that bad. I completed Halo: Reach on Legendary (solo) and skipped no enemies, with only a couple of exceptions. I did Crysis on Delta. I did HL2 on hard.
Yet when I go online, I just get wtfpwnt most of the time. In the case of Halo, sometimes I have good games, often I have bad games, and while my KDR is currently above 1.0 (but trending downwards), I still feel basically bad at it. Most games are composed of heading round a corner only to get spammed with 2,000,000 grenades and a rain of melee hits. Every game seems to have someone who's just so stupidly good it makes me want to give up.