I can't say I enjoy Howard Stern at all- a lot of the humor isn't as much offensive as it is stupid. I'm an information junkie, and hearing fart jokes and anatomical references isn't my version of entertainment. Is it sometimes funny, yes, but not worth my time.
Don Imus is like Howard Stern with an IQ, and actually has guests of some importance, Senators and influential members of the media call in on a daily basis.