Right off the bat, I'd like to say that this is the best movie in the series by far.
The acting was really good. It wasn't the best, but Johnny Depp, as always, redeems any crappy acting of the other characters. He executed his character perfectly. If you don't know Jack Sparrow - I mean Captain Jack Sparrow, I heavily recommend that you watch this movie just for him. Johnny Depp plays the eccentric and puzzling pirate accurately. He gets all the facial gestures and little quirks stunningly well. And to top it all off his face is perfect for the role. Orlando Bloom as Will Turner, Keira Knightley as Elizabeth Swan, and Geoffrey Rush as Captain Barbossa are also amazing, but Johnny Depp knocks them out easily.
The special effects were great as well. The boats looked awesome, and the skeletal versions of the Black Pearl crew were smooth and awesome. The sword fighting choreography was perfect and fluid. The soundtrack is magnificent, the famous "He's a Pirate" being included.
Overall I give this movie a 9/10. It's great fun for anyone around and above their teenage years. Definitely watch this movie!