Inspired by an amyblue comment on the C'mon Kids thread, what examples of 'sell out' and 'not sell out' pop albums can you think of?

By sell out, I mean a deliberate and conscious decision to ignore a band's normal style to pursue a 'populist' sound in an effort to achieve commercial success.

As a side point, you could argue that Blur's Parklife album was a deliberately 'pop' album, but it seemed a natural evolution of their sound and just happened to have very strong songs. I think amyblue's point was that The Boo Radley's Wake Up Boo was a pop album that really didn't sit comfortably with the rest of their discography (hence the return to experimentation on C'mon Kids).