List of brush sites!

www.deviantart.com is actually really nice. I get most of my brushes from there.

Well - funny story. I just upgraded my Photoshop from CS4 to CS5, and everything got deleted. So right now, I have no brushes, no smudge settings, nothing. I'm so lazy to go download them again. :(
 

Added Deviantart now!

That have happen to me to, but just download a bit every time you use photoshop and alot will be back after a while.