Ong Bak --Cave scene at the end. For those who havent seen this movie, check out this review, its dead on the money:
http://www.opuszine.com/movies/review.html?reviewID=245
Enter The Dragon-- Bruce Lee against the army in the underground
Kiss of the Dragon--Jet Li against the French Police Karate class
Saving Private Ryan- maybe not a fight scene but the kick ass opening beach fighting scene
Return of the Dragon--Bruce Lee vs a young Chuck Norris
The Matrix- Lots of sequences floored me, although as time goes by this movie is losing its wow factor compared to the real deal like Bruce Lee