re: campiest movie you've seen?

For anything like a big budget film - Rocky Horror Picture Show, Flash Gordon and Ice Pirates have to be at the top.

As an honorable mention, Mel Brooks movies have an element of camp that works very well, too.

Plenty of "B" movies are campy, either by design or a consequence of the way they're produced. John Waters' films, as well as those of Ed Wood are classic examples of this.