From Pandora with love...

I found these bands on myspace/last.fm that I hadn't heard of before, due to Pandora. Check them out:

hard-rock:

mojo rib
stereo fuse
pitbulldaycare
100 watt smile
Alkaline Trio
Gold Finger
Rainer Maria
Pleasure Club
Nightwish
High and Mighty Color(japanese)
Fly Leaf

Surf-rock:
The Ventures
Los Straitjackets

Classic:
Christine Fellows

Bluegrass:

Old Crow Medicine Show