The Dark Knight - Those annoying, wise-cracking cops, during the epic Batpod/armoured van chase, took away most of the tension from the scene IMO.
Kingdom of Heaven - Orlando Bloom during the film's action scenes has no presence at all, even though he turns in a strong performance, his supporting actors constantly overshadow him.
Harry Potter and the Goblet of Fire - The awkward Haggard "love scenes" are just terrible. This is my favourite Potter movie too, so these minor moments just slow down the film's momentum too much for my taste (especially since the lady had no relevance in the future movies).
Unbreakable - Near-perfect film, but the very ending, with the closing texts verifying what happens to a certain character after the credits roll, is a bit cheesy and over-the-top since it's not based off a true story.
Jackie Brown - Such a great movie, if it wasn't for the sometimes excruciatingly long runtime kicking its way in, this would be my favourite Tarantino film because of the first-rate performances he gets from every actor.