So what is the worst movie you've ever seen in a theater, Gentle Reader? Not the one you thought afterwards 'I want those X hours of my life back' about, but the film about which all rational thought screamed 'how could this film have even happened? WHO THOUGHT THIS MADE SENSE???' as you left your seat, and perhaps even in the middle of the night you lay there staring at the ceiling wondering how anyone sane could've permitted this film to see the light of day.
Mine's a toss-up: either the preview screening cut of Kurt Russell's Soldier (which I even walked out of), or Cloverfield (aka The Blair Monster Project), which only took myself and doroc_sabah the length of a hallway and one escalator to enact an entire Statler & Waldorf routine about, without even realizing it.