Best Joke in the Whole Movie

In my opinion, the best (and smartest) joke in the whole film is Terrance and Philip's "Classic Canadian Joke" which they perform on Late Night with Conan O'Brien.

For those who don't remember it, this is how it goes:

Conan asks Terrance and Philip: "your show has been accused of being nothing but immature fart jokes, what do you say about that?"

To which Philip replies: "that's not true Conan. Take this classic Canadian joke for instance."

Then both Terrance and Philip clear their throats and put on fake moustaches, after which Philip says: "excuse me Terrance." To which Terrance inquires: "yes Philip?" Then Philip jumps up and farts on Terrance, blowing him off the couch and into a drum.

Now to most people, the joke here is that Terrance and Philip just prove their critic's point that indeed all they do are immature fart jokes. However this is not true at all because, in reality, this joke is not actually a fart joke at all. In fact, this is a bait and switch joke. By replying to Conan's question about their show being nothing but fart jokes by saying: "that's not true" and then offering to perform a joke in order to prove it (and reinforcing the set up by donning a moustache), Philip prepares the audience to experience something other than a fart joke. However, when the punchline comes and he farts on Terrance as he does, Philip switches things on the audience, giving them the one and only thing they were specifically not expecting.

As such, the joke is actually a bait and switch rather than a fart joke, demonstrating that Terrance and Philip are perfectly capable of humour which transcends mere fart jokes, but without actually having to break their typical format, making the whole thing all the more brilliant.

Absolutely genius.