The extended versions are not only superior in terms of bonus material, but I also found that the video and audio are a notch above the theatrical versions.

As far as the added scenes, they're not only fun to see, they also (as the case was with the Two Towers) vastly improve upon the film. The added scenes with Faramir, Boromir, and Denethor, for example, even add some continuity that was missing in the previous version.

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Originally posted by: TheSessler
I especially love the end of TTT when Merry and Pippin found Saruman's stash: classic.

I love that part too. Even funnier was that Saruman chastised Gandalf for smoking "the halflings' leaf" when he had his own stash of pipe weed!