Late to this thread, but my worst drink was quite memorable. I was in the French quarter in NO, and asked a bartender for his best personal drink. I rarely order from the menu. What I ended up with was some sort of martini concoction that had olives, vodka, pickling juice, and possibly some jalapeno juice. I choked it down and made a note never to return to this restaurant. That is the first and only time I have ever been burned by that request.