Pirates of the Caribbean was crap. That's my review.
It's not the rehashed jokes, I wouldn't have minded that since they were thoroughly enjoyable the first time. Or the CG being a little over done, that is expected from a movie based on a ride where fire is created by shining a light on a sheet with a fan behind it. Even the obligatory whoring out the end with an unsolved mystery to get people to see the third movie would be okay, as long as they gave me a full movie worth the price of admission. Instead, they had one movie idea and decided to make two movies out of it.
I'm not against sequels, I think Spiderman, Back to the Future, Indiana Jones, Star Wars and Toy Story got it right, just to name a few off my bookshelf here. Pirates however, took the Matrix approach -- sacrifice the second movie for a decent third (well, I certainly hope the third is better ;). Lord of the rings arguably falls prey to this too, being one nine-hour movie. But each one has a proper story, a villain who rises to power and then falls, and a resolution.
Watch this episode of Ask A Ninja for a good review of the movie.