I've got plenty, heh.
Matrix - When Neo awakes as The One. Absolute class, will live on in my memory for a long time.

Star Wars: Empire Strikes Back: "I am your father" - come on, who doesn't love this part?

Star Wars: Revenge of the Sith: Obi-Wan's and Vader's lightsaber fight.
Serenity: When River kicks ass. Amazing... like she was dancing, an art within itself.
The Good, the Bad, the Ugly: When they all have a showdown at the graveyard, wow.

Harry Potter, The Chamber of Secrets: When Harry speaks parsel tongue, all of the peoples reactions were great.

Spiderman 1: When Peter first discovers his powers, and kicks Flash's ass was cool.
Lord of the Rings: The Two Towers: When Eomer shows up and they ride on the Orcs... and Sam gives his speak... amazing stuff, truly an epic story.

Lord of the Rings: The Return of the King: When Sam carries Frodo up to Mount Doom... wow... just... wow. Can you think of a more moving moment?

Seven: The Ending, probably one of the best endings for a film ever... what a twist.
Anyways, those are some of mine, what do you think of them? And what are yours? And what do you think of others?