Haven't walked out of any movie largely because i'm damn good at decifering the worth of a film from it's trailers (though Jack fooled me something awful). I would have walked out of
McHale's Navy but i was with a friend and his mom, so I couldn't; and the only reason we watched was because she got free passes and we had nothing to do that afternoon. After the movie, she apologized profusely and bought us dinner. That's how bad the movie was.