I think there's another recent thread along these lines.
I can't remember who said it, but there was a comment about the fact that however cheesy or unpopular a band was, if your a fan, then it wouldn't be considered a "Guilty" pleasure.
I agree with that sentiment.
There is however one example I have that I would truly consider a guilty pleasure. Even though I love these tracks, I rarely listen to them, for obvious reasons.
TBH, I sort of feel that way about Michael Jackson as well.