Spider-man 3 is my least favorite of the series, but I don't hate it as much as so many. My biggest gripe is really that there is just too much for one movie. In reality there were four villains, and none got the respect or attention they deserved. IMO, Harry/Goblin should have been the focus. Sandman should have been left out. Venom, if he must be included, should have simply been an instrumental character, but I'd rather they had focused on the "fourth" villain, Black-suit Spidey. Peter's own darkness as he tries to battle Harry were more interesting, and I personally would have liked to see Harry never get redeemed. Once Peter overcomes the symbiote and defeats Harry without giving into his most base emotions, then we could see the symbiote crawling off to find Eddie Brock, and then we're in a demanding place for a sequel while still having produced an enjoyable and not overflowing film. I was disappointed with the film overall.

I have to be honest, since this thread is discussing the merits of films at the moment, I personally enjoy X3, and while it has some flawed character usage and some cheesey RPG elements (Level 4 mutants?!), in many ways it's my favorite of the trilogy. It takes risks and alters/kills major characters. It is emotional. It didn't get old to me as quickly as the previous two did. It's exciting. And it has far and away the best soundtrack of the trilogy. People talk like it's a horrible movie, but it's much better than the X-men prequels that don't even fit the continuity.