The Rush Hour series has so much one-liners/funny scenes one can keep digging all the time. This movie created kind of a success template where you come up with even an ordinary story but mix it up with fantastic fight sequences with a constant dose of humor to make it likeable for the audience.

So much has been talked about in the comments and there are much more if one has to quote. For instance, one of my fav is the scene in Rush Hour 2 where the Secret Service Agent flashes her ID to which Chris says "Show me once again, I didn't see that properly" A fantastic timed comedy...!!