Psychonauts is a very fun game. It's also on sale for $2.00 on Steam.

[communist unity (comm-unity)]

http://store.steampowered.com/app/3830/
It's 2.00 USD through Thursday. The best two dollars you've ever spent on a video game, guaranteed.

Personally, I think it's a very enjoyable concept of a game. It has it's flaws, but it shapes up to be a comical, clever platforming game that's one of a kind. It's also made by the same guy who was behind the first two secret of monkey island games and grim fandango so there you go!

...of course, I could finish writing my entire essay on why it's one of the best games to grace the concepts of platforming and 3D gaming itself, but I think I can just save us a bunch of time by linking to Yahtzee's psychonauts review instead.
_{it's sale on steam is also important enough to make me come out of lurking like this. so hey}

[Edible]

Was hoping it would go on sale over the holidays.  Buying the hell out of it now.

[Spidere]

I still have my physical copy. I loved it while it lasted, just haven't played in such a long time.
It's a great game, but, like every Tim Schafer (Don't know how to spell it) game, it just wasn't bought, have you ever played Brutal Legend? Incredible game, but had awful sales.

[Edible]

have you ever played [any game Tim Schafer has worked on]

Yes.

[Spidere]

Yeah, he's one of the best out there, possibly better than Hideo Kojima, but that's more opinion.

[Paul Debrion]

I just bought it, it's downloading right now.

[Third Eye Lem]

I have my CD version still. Good game. Last I remember, I was trying to 100% Black Velvetopia, but I got distracted and I changed computers multiple times. My only gripe is the somewhat uneven difficulty curve when it comes to jumps, and the fact that it's possible to miss all the collectibles in the camp after a certain point, so it's impossible to 100% the game. Sad, isn't it? =P Still, I've yet to beat it, so I'll look into installing it again later on.