I'm not too picky when it comes to film. Sure, many films I've seen aren't masterpieces, but if I'm entertained, then they did their job. Then there's the fact that I can be pretty picky about what films I actually watch. If the trailer and/or summary seems interesting, then I'll give it a chance. Most of the time, it works. Even all the horrible direct-to-video Disney sequels don't bother me too much since I decided to ignore them and hence I haven't seen most of them.
But if there is one movie that actually made me cringe because of how bad it was, it has to be Transformers: Revenge of the Fallen. The first one was a decent popcorn film. Not a masterpiece, but it at least had a coherent and easy-to-follow plot. RotF had...pieces of a plot thrown about. There were some cool ideas, but they never really went anywhere. The humor was misplaced and it, along with the excessive swearing, really distracted from any serious tone they might have been going for. In fact, you know what it reminds me of? It reminds me of a lot of fanfics I see: decent idea, but the author has no developed skills at storytelling and so the entire thing is a mess.