I am not sure I can think of three used games to get. I have been tempted by a $14 Crackdown though. I will have to go in and look around to see what Civilization Revolution and a few other games are going for used (not that I am going to have time for much of anything with Fable 2 and Fallout 3...
I got my first 360 in January 2007 and I am now on my third unit. The first one red ringed and they sent me a replacement unit in which the DVD-ROM stopped working after about two weeks.