What sites/apps do you guys use for discovering music?

I use to have a ton of sites bookmarked and lost them all a while ago and I remember there being quite a few good websites I only saw mentioned on a couple music forums a while ago.

But other than sites like last.fm, music-map.com ect. What are some useful sites? Stats.fm app was also pretty useful since it told you what key the song was in for mixing.