I think in keeping with the spirit of the thread I'll offer up this bit of commentary (and because I like the look of my own words):
Sometimes I go see a film I know will be bad, and thus it's not that big of a disappointment or it's kitschy good (Battlefield Earth, Spice World, AvsP, any Saturday Night Live derived film), and sometimes I go to a film that I highly anticipate and it turns out to be utter shit (Batman and Robin, Johnny Mnemonic, Judge Dredd). Then sometimes I see a film I don't think I'll like and I actually wind up enjoying it (Fantastic Four, War of the Worlds), and then sometimes I go see a film I don't want to see and it winds up being the most painful experience... There have only been two films I've seen in my life that I've considered walking out of... the first was a Problem Child sequel I saw in my teenage years, and the second was Terminator 3.
I didn't just hate T3, it pained me to sit through it. It was after watching T3 that I realized I didn't like either of the previous Terminator films either, and then by extension that I didn't really like any of James Camerons films... no, not even Aliens, although it's the most tolerable of his repetoir.
Hmm... can I add True Lies to my list as well... I'd blocked it out of my memory, but when that Uzi fell down the stairs, yep, I was ready to leave.