I'm not sure how much of a gamer you are, but if you're looking for a game you can just pick up and play casually for short periods of time, try
Snood. It's cheap, it's shareware, it's a knockoff of an '80s arcade game, but it's lots of fun and you can play a full game in 5 minutes or so. Fully mouse controllable. A lot of my college friends really, really obsess over this game.