Most Spinal Tap-like band
I'm going with Iron Maiden.
Just watch this movie then immediately watch the "Number of the Beast" video.
(great song btw, nothing that I know of compares to the awfulness of Spinal Tap music, and yes I know it's suppose to be bad)
If you don't read the newspaper you are uninformed. If you do...you are misinformed---Mark Twain