I got Guitar Hero: Aerosmith (360) for 5 bucks new, the guy told me the price went down today. Maybe he made a mistake but it's brand new, not even gutted.
I found 3 XBOX 360 games today at Best Buy for 10 bucks each. I'm sure they are usually only $20 games elsewhere but still not bad. Games are:
Vampire Rain
Viva Pinata
Ninety-Nine Nights