One little moment that always makes me laugh.
Right after the pizza man shows up and Lewis goes postal on him and pulls him inside the apartment, he gets him in a head lock and rams his head through the wall. What kills me every time is that when he pulls his head out of the wall and says "Extra cheese?" before passing out his hat is missing, it's still inside the hole in the wall.
"Mr. Treehorn treats objects like women, man."