I've been lucky enough to avoid a majority of bad movies, but unfortunately, there are two I really can't get over.
One of the two movies that come to mind is 47 Ronin. I can't remember why I found it so lackluster when I watched it on the plane that time, but either way, there was something I despised about it- which was a shame, too, because the kitsune near the beginning kind of hooked my mythology-loving side. I'm just glad I didn't pay to see it in cinemas.
The other? It's kind of a cliche response, but... New Moon. I was forced to watch it due to it being one of my set texts in Media Studies, and, to be honest, it hurt. It just hurt my spirit. But if I may elaborate... not only is the subject material- that being 'vampires' and 'werewolves'- horrendously wrong to the extent that it honestly offends me, but I also found the story cliche, the characters unmemorable (except for that Aro guy somehow. He's the only character whose name I could really remember after watching), there were too many characters who only had a bit appearance and never had much of a coherent role/development, and the acting... well, the actors just looked and sounded like they were bored and just wanted to be out of there. At least the shapeshifter (fixed it) CGI was pretty cool, though.