Surprisingly, a dud. Endless grey monologues, pointless side-plots, key uncharismatic performances from, to start with, Hill and Otto. None of the wistful earthiness and even passion of the first film (perhaps due to the absence of Bean and Holm). Brad Dourif's small role as Grima Wormtongue is so good that the film plunges into dullness on his departure. The reliablity of Wood and Astin bring the only solidity.
The Two Towers utterly fails to captivate. Focusing far too much on the central conflict of Helms Deep, Jackson's film manages to muddle and rush the stories of the hobbits transporting the ring itself as well as distractingly lose track of and re-find Merry and Pippin during their journey among the Ents. Beefy exposition gives way to too-quick tying up of loose ends and emotion is sacrificed.
The strongest of the three - a perfect balance of relational, emotional, and plot-driven drama. Much more subtle than the others, with Andy Serkis and Bernard Hill stealing scenes left and right and powerful performances also by Viggo Mortensen, Miranda Otto, and Sir Ian McKellen. A beautiful climax that still makes me weep after 10 years of viewing.