TC, do you have a job? Try making friends with your co-workers. You see them nearly every day as it is, so go do stuff with them. Suggest you go out for drinks one night, or throw a party and invite everyone over. Hell, even if you don't really like some of them very much, you'd be surprised how different people can act when they are out of a professional enviroment.
If you are still in school, then its much easier. Talk to your classmates, go to school functions. Colleges ALWAYS have something going on, period. Even if they are just sporting events, you are guaranteed to meet people. If you aren't in school, but live near one, this advice can still apply. Most college-aged people aren't too picky about who they hang out with; get to know someone even decently well and you'll likely get invited to parties and such (provided, of course, the person you are friends with does stuff like that).
Other than that...I dunno. Have any hobbies? Go find like-minded people to share them with. Since gaming seems to be your thing, talk about that. Its not nearly the taboo that it once was; in fact, most guys in the 16-24 range are almost guaranteed to play video games on at least some level. It might be that they only play CoD or Halo or something, but hey, thats at least some common ground, right? And from there, once you can build a rapport with the person, you can start branching off into other things.
The main key is confidence, really. Just be friendly, and as outgoing as you can.