I'm great at FPS games, mostly because I have what I term "battle sense". Essentially I can use tactics and cover to come out on top in most fights, whether it be a knife fight, sniper battle, or dogfight. Combined with decent reflexes, I usually end up on the top of the leaderboard in games such as BF3. And in singleplayer, playing on anything except the hardest difficulty is a no-go.
In RTS and strategy games, I can hold my own, although I tend to "turtle" too much.
I also love racing games or flying games, any kind of vehicle is great by me.
However, when it comes to sports games and games like super smash bros, I get schooled. To me, those games are just button-mashers. My weakness is games like these and my friends know this and frequently take advantage of it to get even with me for beating them in shooters or racers.
Bottom line is, everyone has games they're good and bad at, just because you suck doesn't mean you can't enjoy a hobby, and this isn't just regarding gaming. Also, you can always get better. I used to suck at FPS games a few years ago, now I'm pretty decent. Practice makes perfect.
EDIT: Oh, and if you listen to people while gaming multiplayer you need to reconsider. Even if they are over the age of 13, they are still likely to call you a "fag" or "gay" no matter what you do, win or lose. I can't count how many times I've been called a hacking fag, or a vehicle whore.