Xbox Games:
Angry Birds (in case my brother wants to play it; only got it because it was free for a limited time)
Asphalt 7 (beat it, but can't bring myself to delete because I'll lose my progress, and if I decide to play it again later, I'd have to reinstall and beat it all over again)
Civilization Revolution (just the demo, going to try it out this weekend and consider a purchase since it's $0.99 this week).
Jetpack Joyride (would have bought this if it was a paid app, best free Xbox game BY FAR, in my opinion)
NBA Jam (wish they'd update the rosters, but a fun game nonetheless)
Skulls of the Shogun (haven't gotten around to playing it much yet, even though I've had it since it launched)
Tiki Towers (got it for $0.99 as a Red Stripe Deal, but haven't played it since I bought it; liked the demo, so figured it was worth a buck)
Wordament (put a LOT of time into this when I first got my device, but stopped playing it after it reached iOS, for the most part)
Xbox SmartGlass (not sure why it's considered a game...)
Non-Xbox Games:
Farkle Dice (free and LOTS of fun)
Royal Revolt (also free, also a lot of fun)
Tile Path (got it for free when it was on-sale, it's a pretty sweet puzzle title)
Where's My Perry? (got it when it was initially free; keep it installed in case my brother wants to play it)
Where's My Water? (same story as Where's My Perry?)
Wordness (just saw it get an article on the main site and figured I would try it out, though I have not yet)