You know what is the funniest with cats? When they get all belligerant and start whacking you (or a cat toy, or anything really) with both their paws. Like they are trying to box with you or something!
I recommend playing with your cat, with a laser pointer! My kitty Inky goes NUTS with this. You can make it disappear underneath a closed door, and he will stare for a half hour windering where it went!