I saw 311 live. Pretty awesome, and the drummer played an insane drum solo. Creatures and Down were pure awesome. \m/
Sublime's great. So many classic songs, and IMO Bradley's underrated as a guitarist. Same in the End is probably my favorite tune. I never got the chance to see Sublime live (was still young when Bradley died) but I saw Fishbone live and they played an awesome cover of Date Rape. \m/
The Flaming Lips are pretty great. So far I've only heard Yoshimi Battles the Pink Robots. Some great songs on there, especially Don't You Realize, which is absolutely heart-wrenching. I once saw Beck live and they he actually played an acoustic cover of Don't You Realize. Was so beautiful...
Jane's Addiction is great. Ritual De Lo Habitual is just a kickass record.
I like Modest Mouse. Some really great songs, and I probably need to get more of their music.
Cake's great. I'm an oddling in that my favorite album of theirs is actually Pressure Chief. But what can I say? Wheels, Carbon Dioxide, all all the other tracks are just such perfect pop-rock. And End of the Movie is so poignantly simple yet beautiful. I also saw Cake live. \m/
Anyways, I have hundreds of favorite bands, as well as tons of artists that aren't in the rock genre, so it'd be impossible for me to list 'em. I'll just respond to whatever interesting bands are mentioned here.