I've had too much sugar lately

Screw whatever you're doing right now. Music = Truth.

Pandora.Fm
(Pandora meets Last.Fm)
Hype Machine (Lots of music from weblogs all over the internets. If you have an account it'll scrobble to Last.Fm)

There's other sites out there and what not that do better jobs than these sites do (like Skreemr, Songza, Grooveshark, and Seeqpod), but these guys scrobble to Last.Fm and I kinda prefer them, so stfu!!!!!

(and if you're clueless on what last.fm and scrobbling is and want to find out more about it, go here.)