Id probably have to say "The Karate Kid" if you actually called that kung fu, otherwise id have to say Bruce Lee, in Enter the dragon, though when I was about 7 I saw a movie at a friends place who was a Taekwondo person, and saw some highly elaborate fight scene on ladders and only until like 3 days ago I realised that was Jet Li in one of the "Once apon a time in china" movies, cos I just saw a trailer on my 30th aniversary edition dvd set.
Funny how ive seen most of jet li's movies but I havnt seen that one, I saw "Once apon a time in China 2" and thats it.