The Bus

Doesn't count if it's your band or your accountant's band or your nephew's band...

De Vil -- very atmospheric, soundtrack-ish instrumental stuff...

DodgingCars

There's so many bands on Mp3.com right now, that I don't know if this is really a good poll. Many independent bands (even those that are signed) are on mp3.com.

With that said:

Thrice is my probably favorite.

My girlfriend's brother's band is on there too. They're pretty cool (shameless plug).

9 Litre

AtlDVD

I like Kenny Howes and the Yeah!
http://www.mp3.com/kennyhowes

and

Solution Science Systems
http://www.mp3.com/solsci