[NyteSky]

What has stuck with me most is Gandalf's struggle. Both with the Balrog when it happened and when everyone was grieving for him and then we he returned as Gandalf the White. Tragic yet overcoming in the end, classic combination. Second would have to be the hunt after Merry and Pippin. Very moving how the remnant of the Company worked so relentlessly to get them back.
Of course next time I read through the books another scene might jump out at me. They're full of great scenes.