The first time I saw Fellowship in theaters was about three days after the movie came out. I had only read as far as the West-gate of Moria, and so everything after that in the film had me absolutely on the edge of my seat. And when Merry and Pippin were taken by the Uruk-hai at the end... Panic. Complete and total panic. I catapulted out to our car and flipped ahead into Towers just to find out what happened to my hobbits!
My resounding memories from seeing Towers on opening day are my dad and I sitting in the theater waiting for the film to start and reading aloud from The Silmarillion, and afterwards, me standing up and yelling at the screen because Shelob wasn't in the movie.
For RotK, my dad took my brother, myself, and two of my friends to see it on opening day. My brother and I were hobbits, one of my friends was an elf, my other friend was a Nazgul, and my dad wore his kilt.

It was really really cold that day, so of course Dad wasn't too happy, but there was also about six or seven inches of snow everywhere. My poor bare feet almost froze! During the film, when Shelob is sneaking up on Frodo, my Nazgul friend started humming the theme from Jaws. Most lofty.
Abedithon le,
~*~Aranel~*~