Two Towers is my least favorite part too... I love the return of Gandalf, the 3 hunters, Merry and Pippin with the Ents, Faramir
But the battle at Helm's Deep ruins it for me... it's too long for me.
I LOVE the third part, it's one of my favorite movies of all time. Everything from the other 2 movies comes together, and then the action REALLY begins. But yeah, the trilogy is mostly about the journey... Why certain characters are the way they are, what it's going to take to get rid of the evil. Plus, the scenery and the music. Still love them!