I can't speak to the PC version, but I've played the hell outta RB1 and 2 on 360. Personally I love'em for challenge and social fun. And oh ya -- getting slightly intoxicated and having 3-4 people trying to rock out is hilarious. Success is all high fives and good sense of team accomplishment.

But as far as the genre goes, I've found that anyone who really enjoys music and listens intently usually likes the game. And if you haven't tried to play a guitar, it gives much more appreciation to that as well.