You know you've been watching too much LOTR...
...when you actually start listening to the design team commentary of The Two Towers.
That said, I highly recommend the Director/Writer commentary for both The Two Towers and The Fellowship of the Ring, which are really interesting from a writer's point of view as they talk a great deal about what to put in and what to leave out and what's critical to the story.
And the actor's commentary is worthwhile just to listen to Billy Boyd and Dominic Monaghan tell you why The Two Towers should really be called Pippin and Merry Save Middle Earth.