Whichever one has the giant spider in is the best.
Shelob is the sole redeeming feature of the book, and the high point of the films. The films are very accomplished and well made, but hollow and tedious. I enjoyed them at the cinema, but watching them subsequently...GOD THEY GO ON!!! plus it's hard not to hate hobbits. They are so lame! Shaved Ewoks...
A cut above most blockbusters, but still nothing to rave about. Jackson has done much better. And worse!