The song which has caused me most trouble over the last few years is certainly Crawford Howard's parody on Bogle's "No Man's Land". Some folk don't see that it's a hit at bad singers and take it at face value.
I gave up singing it after several threats of violence. I don't know if anyone has been brave enough to record it. Of course, if you want to upset some people in parts of Ireland or Scotland "God Save The Queen" is a sure thing.