TOD:
Hard to say. I'm a big eater in general, which is something I try to control. Sometimes. But I'm absolutely out of control in buffet situations, so a few of my record breaking achievements have to have taken place in such venues.
Okay, wait, it isn't at all hard to say. By definition, the winners are the two or three times I actually ate myself into being sick later. I always recall one in particular, and I'll think of the other one(s) sooner or later. That one time, I had stuffed myself with snacks in the car on my way to a friend's place that was over an hour away, followed by eating a lot there (partially out of politeness, and we probably had a couple of drinks which made even more food go down easily), followed by inexplicably stuffing myself again later on the hour-long drive home. In bed that night, I still had an extremely uncomfortable overstuffed feeling, and before long I was in the bathroom praying to the porcelain god. This was pure self-inflicted misery, and there's no discernible explanation for it.
After typing that, I still don't recall other times, but there were indeed a couple.