Psychonauts

Heh. I'd have to say Costume Quest or something by Doublefine.

Edit: Or Sequence.

Trine 2

Faerie Solitaire.

Secret of the Magic crystals!

This is a fairly cool, mild mind fuck you pulled off.

Also: Send them all Dippin' Dots. In the mail.

Garry's Mod perhaps?
Edit: Audiosurf is also great if you are into music.

Cool! So that's what it was!

Also, my suggestion for a game is Beyond Good & Evil.

CS

Shoot many robots!!

Star Wars Knights of the old republic or Dustforce!

That's a nice one xD

counterstrike or halflife 2 would be cool, or trine :D

poker night at the inventory copies :D anyway gratz guys

Terraria would be nice

Terraria ftw ;)

Deus Ex GOTY, Deus Ex Invisible War, Puzzle Quest 2, and Virtua Tennis 2009.

Oh and Quake, the original.

All Zombies Must Die!

Magicka is pretty cool.

Zombie Shooter 2 would be awesome! :)

Terraria! =P

Dustforce would be great.
Nice April joke :P

Binding of Isaac, awesome game.

awesome!

Gotham City Impostors and Trine 2 are under 10$ but that's ending soon.

Terraria is a nice little game.

Magicka is quite fun especially if you have friends with the game.

Shank 2 has a great combat system.

Binding of Isaac is a difficult game but oddly addictive.

I have yet to find anyone that does not like Plants vs Zombies.

Psychonaut is such an underrated game. It's so good.