I'm a big fan of Sequence, and of Rock Band III (sadly unavailable to me except at friend's houses). Does the PC gaming space have some really solid rhythm games? I've tried a few free games and demos, but a lot of PC music games either have severely limited procedural systems (allow you to pick whatever music you like ... but only really work some of the time) and/or don't have particularly rhythmic play in the first place (Beat Hazard and Audiosurf come to mind). Also, PC music games tend to only incorporate the radio edits of explicit songs, which is a real turn-off.
I doubt there's much out there like Sequence--it's relatively difficult as a rhythm game, has great licensed tracks, and has a totally-out-there gimmick that really works (the three-panel, turn-based RPG mash-up). But I can dream.
Any suggestions? Otherwise ... music and rhythm games on the PC! The woes of keyboards that don't support 4 button presses at once! Discuss!