Many of mine have probably be said but I'll say 'em again.
Phantom Menace - QuiGonn Jinn and ObiWan Kenobi vs. Darth Maul
Army of Darkness - Ash's encounter with the Deadite, where he prevents the blacksmith from being squished.
Army of Darkness - "Say hello to the 21st Century!" in the Death Coaster's maiden voyage.
Army of Darkness - "Lady, I'm afraid I"m going to have to ask you to leave the store."
Rumble in the Bronx - the warehouse fight
Jackie Chan's First Strike - Chan demonstrating his black belt in "Ladder Fu"
Police Story - an older Chan flick with one of the best end fights I've seen and in a mall no less.
Deadly China Hero - numerous fight sequences with Jet Li as Wong Fei Hong but my faves are Wong vs. the High Priest (NO SHADOW KICK!) and his return at the end (Centipede Fu vs Chicken Fu!). However his 2 pupils fighting the High Priest was also pretty good.
Hard Boiled - its 3 long gun fights with the hospital as the best one
Broken Arrow - "Please do not shoot at the thermonuclear DEVICES!"
Magnificent Seven - its the theme
Blade - opening sequence in the slaughterhouse and the leadup to the final duel
Kiss of the Dragon - when Jet Li assaults the police station, especially in self defense class and against the twins
Big Trouble in Little China - I can't nail any one thing down but most seem to involve Egg Shen (reminds me of Uncle from Jackie Chan Adventures), Jack or Wang (gee, that narrows it down).
The Princess Bride - Final duel between Count Rugan and Inigo Montoya "Offer me all that I desire!" "Anything you want! Please!" "Give me back my father you son of a (w)itch!".
Dirty Harry - "I know what you're thinking. Did he fire 5 shots or 6? In all the confusion, I lost track myself. Seeing how this is a .44 Magnum, the most powerful handgun in the world and can blow your head CLEEEEAN off, the question you should be asking yourself is: do I feel lucky? Well do ya, punk?"