When I saw the thread title, I instantly thought of the LOTR trilogy. The only positive thing I'll say about the LOTR trilogy is that I think the art department deserved the oscar(s) they won. I also thought the casting was good, but the Hollywood'y-fied DRAMA-AT-EVERY-TURN, plus the "we must have a bigger female presence in order to draw couples in to the cinema so we'll come up with this horrible cliche plot of Elrond not wanting Aragorn to be with his daughter" was retch-worthy.
Others have already mentioned steaming dumps like Prometheus and DKR.
I watched Batman Forever again in the last few years, not long after watching the better films (Batman, Begins, Dark Knight). Batman Forever really is awful. B&R is in a league of its own of course. There's a bit in Forever I'll never forget: Bruce Wayne is visiting Dr Chase Meridian for some reason; she's in her office I think. The doors to her office are closed, and they're these very tall doors, quite solid and expensive-looking. Wayne hears some kind of scuffle inside (because she's working out in her office, as you do), and breaks through the doors. The doors actually come off their hinges like he's Superman in disguise.
Hmm, I just remembered another bit, absolutely freaking hilarious, was he hanging from the ceiling in wait?:
https://www.youtube.com/watch?v=sws-buryO24