They've gone through some radical changes since they started out in 1986. Their late 80's stuff is very punky, thought I've never really taken the time to get into it, nor am I really a punk fan. Their mid-90's albums (
Superstar Carwash and
A Boy Named Goo) are a slightly less commercial, kinda hard rock version of what they do now. Very Greenday/Smashing Pumpkins-ish (sorry, they're the only bands that come to mind ATM) Then ofcourse you've got everything from
Iris onwards which is softer, more commercial (but still good) material. But like the Walrus said, their post-98 stuff can be quite samey.
One song you should check out though is
Lazy Eye (from the
Batman & Robin Soundtrack), great hard rockin' tune.
Probably the only good thing to come out of that movie.