Harry Potter 4 or Harry Potter 3 movie?

Both are great, but I preferred the Prisoner of Azkaban. But You'll have to watch the Goblet of Fire too, in order to be ready for the Order of the Phoenix

Both Goblet of Fire and Prisoner of Askaban are better than the first two, but I'd rate Askaban (3) the better because of Alfonso Cuaron's direction.  It gave it a darker, more dangerous feel and some great visual design.  It was also excellent to see Gary Oldman not playing the villain for once.

I liked the third book better than the fourth, but the fourth movie better than the third.

No. 5 is almost here...