Funniest part(s)???
One good joke is the James Brown car alarm commerical. Very witty.
A sequence of bits when David constantly crashes into stores is very funny and very Blake Edwards.
AND my favorite one is not the golfball hitting tree bit that everyone is talking about. It is the scene where Bruce Willis goes beserk and holds David at gunpoint at the party in the front of the house. "Dance!" (David dances pathetically) "Moonwalk!" (David does the Moonwalk) "I hate that s**t!!!" and Bruce starts shooting at David. I was laughing so freakin' hard at that!