I agree with Superpiggeh, The Last Airbender was horrendous.
Also in my opinion all Tyler Perry movies are ridiculous and bland. They're basically the same thing but with different family organizations. And plus, when Tyler Perry inserts himself into his own movies, it's kind of creepy.
Tyler Perry did plays before he did movies. I used to watch them with my family. The plays are excellent! Well written, dramatic, humorous, and most of all, succinct. Madea was not the main character in any of them.
Once he went Hollywood... well, unfortunately, the success, the people telling him how great he was... Well, it just went straight to his head. Plus, for some reason, Hollywood loves the 'black man in a fat woman suit' thing. I do not know why. Eddie Murphy, Martin Lawrence, Tyler Perry... SERIOUSLY, STOPPIT. It's not funny, it never was funny, it's getting sad, stop.
Another movie that I had the unfortunate pleasure of having to sit through... Soul Plane. It... it hurt my soul, it really did. Just... horrible stereotypes upon stereotypes, with the added addition of 'scared white family in the midst of crazy black people' trope. Ugggggggggggh. Shoot me.
What else. OH! I might get flak for this, but... The Big Lebowski. I won't say it's the worst, because it's got a massive cult following. I just hate it personally. My fiance made me watch it (it's his favorite movie) and as soon as the end credits rolled, I said "What the HELL did I just watch?" Seriously- no plot, no cohesion, just... Yeah.
I did get some lovely quotes from it, though.