I watched the midnight movie and went in knowing that there would be parts left out, and therefore wasn't disappointed a bit. Like many have already said, books are ALWAYS better than the movie.
My favorite part was when Umbridge was taken away by the centaurs and she asks Harry to tell them she's a good witch, and he goes "I must not tell lies"
I also liked gangsta Dudley
the entire theatre was cracking up ... and I loved the battle at the end! I loved the action shots of Harry and Dudley running in the beginning ... I loved seeing the Dementors without their cloaks (okay they were freaky, but cool nonetheless) ... I thought Voldemort's possession of Harry to be VERY cool ... I also like Dumbledore at the end - seeing a much more compassionate side to him talking to Harry while he's possessed ...
Sure I would have loved seeing Neville's parents in Mungo's, or how Percy turns into a bloody git or how the statues come to life and protect Harry ... if I had my way, the HP movies would be the entire book ... maybe in mini-installment movies ... like each book would be 4 movies. Now THAT would be cool
But my two cents, I loved it just as it was, and will definitely see it again soon! I