Band whose style has changed the most

Japan
Lake Trout
The Grateful Dead went through a few different phases.
Originally posted by Tar Zen:
Lake Trout
Oh, definitely!

Dead Meadow
whatever . . . madonna, girl.
U2
Beck
Incubus
Pearl Jam
Deftones
panic! at the disco.
Radiohead (Pablo Honey to OK Computer in 2 LPs…wow…not to mention going to Kid A and then Hail to the Thief)

Most schizo: Primal Scream. You just never know what the hell you're going to get from them.
The Ecstasy Of St. Theresa

Every release seems to be a completely different genre. All very good but I've known people who were disappointed after going to one of their live shows because they expected to hear them play one genre and ended up hearing something completely different.

Also Brian Eno.

My Bloody Valentine started out as sort of noisy Punk and then went to softened noisey Shoegaze.

Idlewild started out a bit similiar but then graduated to a much more astute, more intellectualized British singer/songwriter Rock.

The Beatles

Catherine Wheel - Guess you could say, that Wheel just stopped rolling as they winded down in time to a less than screeching stop.

Fleetwood Mac - Anyone who is familiar with their journey from very early British Blues to their more cerebral yet rocked out "Mysteries To Me" era up to their complete make-over with Buchingham and Nicks, which turned them ultra-commercial, would agree hands down that they have had more than their share of make-overs.

*Bearman, you are definitely right about Primal Scream!

As far as using the exact same music vs specific performances, I have to say Spiritualized. In later years, they've gotten in a bit of a rut with recording what sounds almost like the same old music over and over again; however, each tour presents the exact same music in a completely different manner.
James went from putting out 'laid' to techno dance music and Black Rebel Motorcycle Club is now making roots americana.
Ramones
Motorhead
AC/DC
Bob Mould

Blowoff is like a very, very bad dream…
Joe M., hate to say it but I agree…last night sucked. I just can't stand the people. Blowoff will run its course though, and he'll have gotten a lot of this out of his system. But the people that helped make Blowoff big are getting alienated by it. Unfortunately, the Blowoff record isn't very good either.