Try out the new game Snail Mail from Sandlot Games. My friend Andy worked on this game, and I *almost* got my act together and did the voices for the enemies. Next time I will record the voices the night he asks for them rather than a week later.
Just in case anyone here doesn't have a Gold membership but would like to try out online play... personally, I recommend both Uno and Street Fighter. And as I've already said, I can't wait for the Street Fighter-themed Uno deck.