Also annoying: Nowadays a lot of people know Bo Rhap as the "Wayne's World song," repeating bits of the operatic section ad nauseum. It's fun to play the whole song for these people, because they're often completely jarred after listening to all the lyrics--"Dude, that's about a guy who killed someone!" Some people will just never understand.
EDIT: I am a complete idiot. I meant for this to be a response to the "Something that bugs me about 'Somebody to Love'" thread. Please forgive me.