I loved and still love the first album, it couldn't be any better. Even if you strip away the vocals and the funny guitar noises, you're still left with some bloody awesome old-fashioned riff rock.
Wasn't so keen on the subsequent albums, I found Zack and his constant whining about Leonard Peltier and Mumia Abu-Jamal increasingly irritating.
Oh, and I might as well say now that I love Audioslave, just in case the discussion goes in that direction.