For me, anything that has Shin'ichi Chiba, AKA 'Sonny Chiba' in it is probably one of the
best there ever was. There was actually a story line, and one a moderately sober person could follow. Shin'ichi was amazing.
IP Man already been mentioned but my favorite would have to be Jet Li. Check out some of his best movies if you all haven't seen them already.
Lot's of action.
Fearless
The One
Unleashed
Kiss of the Dragon
Romeo Must Die
Bruce Lee is my favorite Martial Artist of all time though. "The less effort, the faster and more powerful you will be" - Bruce Lee.
ONG BAK. All of them
UNLEASHED (not an actual fighting movie but kick ass)
Blood sport(s) (van damme only)
Only The Strong (capoeira)
All Bruce Lee movies.
And I think i'd consider "The Expendables" a fighting movie. 1 and 2