Re. LOTR trilogy. Fellowship is my favourite, because it's consistently good.
In Two Towers I find the Frodo scenes heavy going, and much prefer the adventures of the rest of fellowship.
In RotK it's the opposite. The Frodo scenes are very well done, but the paths of the dead/Pelennor Fields scenes are hopelessly messed up. The over-reliance on the mumakil and ghost army really spoil it for me. Eowyn's big moment is pitiful.