Bands that drastically changed their image & sound

Adam and the Ants...hardcore punk band to the 'Dandy Highwayman' in the space of a year or so. What made the change even more noticeable was Adam's habit of putting his early punk songs on the b sides of his pop singles - Beat My Guest with Stand and Deliver, Red Scab with Goody Two Shoes, etc.

From Hannett to Eternity wrote:

Blur started as a Madchester/Shoegaze pastiche, then became a modern XTC, then the guitarist left and they became a bizzare mix of indie rock and world music.

I don't see Blur has having changed that much. They were more a somewhat dull (IMO) Britpop outfit to start with (don't see much madchester or shoegazer influence myself), then went very slightly experimental (i.e. pavement influenced i.e. fall influenced) after they lost that ridiculous contrived battle with the even duller Oasis. They remained consistently not-very-interesting thoughout.

Radiohead's my first thought. Specially from the thrid to the fourth album. From class alternative pop-rock to stupid Pink Floydish alternative I-don't-know-what...

radiohead interpol the strokes u2 rem

Talk Talk went from being 80s new romantic popsters to ambient/jazz progressive rockers on Spirit of Eden.

The Notwist went from hard rocking grunge metal to IDM/laptop electronica,