I think that, “What the hell are you doing?!” is right up there, as most people do not realize that there is a method to my madness. Those who know me just shake their heads but know that I will get impressive results.
“Are you crazy?” is another top-10 question I get asked.
“Can you help me fix my [computer/car/electronic device]?” is pretty common.
“I can’t place your accent; where are you from?” is fairly common.
“Why do you act so [condescending/arrogant/smug]?” also places pretty high on the list, as does, “Did you know that you are a real asshole?”.