I enjoy all of them. I like the first two the best, but JP3 is a fun popcorn movie. It has an energy to it that makes it fun, regardless of the crap they pulled with offing Rex.
JP and TLW further the story. JP3 exists just to see dinosaurs again.
And despite it's length, which surprisingly is shorter then both AVP movies, it doesn't feel as short as those. Why? Because JP3 has pacing, it delivers the goods. The AVP films can't even deliver in the action department.