I have never walked out of a theater...I always think "this has to get better" I am always wrong on that.
I should have walked out of "the Three Amigos" .. It was a first date...what a nightmare that movie was. Here it is some 25 or so years later...and it still gets a laugh and a mention for worse movie choice ever made.

The only time I walked out of a theater, was when I was in grade 8 on a school trip to Ottawa. We went into an Imax theatre and watched a film about sports and mountains and stuff. The scenes were shot in such a way that the camera would spin around a mountain top, or slide down a mountain. It was literally making me feel queasy and dizzy. A few of us felt that way, so we stumbled up the stairs out of there, and tried to relax/calm down.