Comrade F
A talented artist with quite a lot of enchanting music. Go over there and show him some love.

Live365
A vast index of online radio stations. You do have to sign up, but they never send you spam, and even a free account gives you unlimited listening time.

OverClocked ReMix
This site has more video game music remixes than you can shake a stick at. The songs come in just about every genre, and it's a great way to relive some of your favorite gaming memories.

Positively Dark
Positively Dark is positively divine. The tracks "Howl" and "Mermaid" are especially recommended.