I love rock band but one thing i wish it had more of is some newer hard rock bands. I mean during the late 90's and early 2000s those bands were dominating radio. And even now, there are plenty of good hard rock bands. Here's some bands i'd like to see: Deftones, Sevendust, Nonpoint, Taproot, Chevelle, Skindred, Breaking Benjamin, 3 Days Grace, Helmet, Ill Nino, Evans Blue, Adema, Korn, Staind, Cold, 10 Years, Finger Eleven, Thornley, Crossfade, Deadsy, Lacuna Coil, Evanescence, Earshot, Egypt Central, Ashes Divide, Tool, Hurt, Seether; really I could list more, but it'd be nice to see at least a few of those bands on rock band.
Also a good progressive rock band to include would be a band called Dredg, who have kind stayed under the radar, but anytime you go to their shows it's packed out. Awesome music.
And what about 311? They could be considered a 90s band because that's when they first came on the scene with hits like All Mixed Up, Down, Come Original, Homebrew and my fave by them Beautiful Disaster. Just some suggestions. Please consider some of them.