What bands totally have a bitchin' live show, but their normal albums sound like crap? And vice versa. Dragonforce has a very impressive sound in the studio, but they can't play their solos live and it sounds like shit.
There are a LOT that sound good in studio, but not live. I haven't really heard of any groups that sound good live, but not in studio. Although that may be because I almost always hear a group's recordings first, so if I don't like that, I wouldn't listen to them live.
