Been exploring the X-Box 360 Live Arcade recently, and I've found some real wonders!

The Katamari series is a must-look for any programmer or artist.

http://www.youtube.com/watch?v=zi3Vr2XLvQA&fmt=18

The most unique game mechanic I've ever seen, and breaking highscores is, rather than competitive, collaborative. The control scheme exclusively uses the two analogue sticks, and nothing else.

If you've got an X-Box 360, download the Beautiful Katamari trial from the XBLA; I promise you, it won't disappoint.

Other interesting demos worth a look are Braid (time-travel puzzler mentioned already on FK), Castle Crashers (by the Newgrounds makers of the Flash and console game Alien Hominid), N+ (another successful Flash game gone console) and Geometry Wars (ultimate particle extravaganza).

That is, of course, if any of you guys ever get any spare time.