The best one I ever had was during a gig with my old jazz-fusion trio at a jazz venue in Bristol. We had just finished a John Scofield tune and were about to launch into another instrumental epic when this I've-had-one-alcopop-too-many student-type came up to me. "Do you do Iron Man by Black Sabbath?" he asked. I looked at him incredulously. "Do we sound like the sort of band that does Iron Man by Black Sabbath?" I replied with a laugh.
We launched into the aforementioned instrumental epic, at the end of which there he was again. "Do you know Iron Man by Black Sabbath?" he asked. "No we bloody don't", I replied somewhat testily. I wandered away from him to try to signal that the exchange was definitely ended and we dived into another lengthy widdle.
At the end, yup, there he was again. "Why won't you play Iron Man?" he demanded. I gave him my very best Paddington Bear Hard Stare. "Oh come on, you must know it!" he said. "Look pal," I said in a firm this-conversation-is-over tone, "just f*** off eh?".
Thankfully, he got the message and f***ed off. I'm pretty sure he was only doing it for a laugh anyway. Perhaps his poncy mates put him up to it.
(I wouldn't normally tell a punter to sex-&-travel, but this gimboid was seriously getting on my toot.)