Games you always look for at yard sales/thrift stores, etc?

[Kane99]

What are some games you are always on the lookout for when you're out and about at yard/rummage/garage sales, thrift stores, antique shops, etc? I am always looking for NES, SNES, Genesis, and most other retro games. I don't see a lot of good retro games in my area when I go out thrifting. Usually all I ever find are sports games or mass produced games I already have or don't want. I am also starting to re-build my PS2 collection and build up an Xbox, Gamecube, Wii and more collections. If I see a cheap game, I will likely pick it up, as long as it's something I can see myself playing. Any rare or obscure games you keep your eyes peeled for? I know to always keep an eye out for games like Little Samson. 

[Scorpion]

I always look for rare PS2, GameCube titles. Sometimes I'll find hidden gems like Rule of Rose or Haunting Ground!