I have vague memories of being trapped in front of the "President Clone" sleeping monk in Spaceship Earth for several minutes as a kid, but nothing as exciting as what some other posters have been through.
I have noticed that there are a lot of stories involving Splash Mountain, and I think I can give some insight there. According to some accounts from cast members elsewhere online, there is something about a water ride that turns people into lunatics; they do thing they'd never do anywhere else. Keeping this thread family-friendly, let's just say that the two main reasons for shutting down Splash Mountain are usually (a) people getting amorous while surrounded by country critters from a buried Disney film (eh, why judge) and (b) people flipping out and trying to bail out before the big drop (which is easily seen from outside so there is informed consent going in; why are you on the ride in the first place?)