I can't get enough World of Goo. The like-nothing-else platformer for the PC, Mac and Wii involves building shaky towers, bridges and other structures out of balls of goo. It's hard to describe, but once you play it, you'll get it. And you'll probably play it for 12 hours -- at least.
Sadly, no one can play World of Goo all the time. You gotta eat, right? Luckily, World of Goo's soundtrack is available for free, so even when you take a Goo break and eat some steak tartar, you can slap on the headphones and enjoy the game's excellent, movie-score-like soundtrack. Oh, and it's free! Really, you can't possibly beat that. Here's where the files live.
By the way, if you haven't played World of Goo, you should. It's great. You can download the PC and Mac version here. And if you sign on WiiWare, you can cop the Wii version.