Geekiest. Punchline. Ever.
Here's a pretty old post from the blog archives of Geekery Today; it was written about 19 years ago, in 2006, on the World Wide Web.
Well, maybe not as geeky as It’s a Gandalf hat!
But it’s up there, and it involves more work. Here’s today’s FoxTrot:

Here’s the spoiler, for those who want instant gratification. Code the short taps as dots and the long taps as dashes. You get the following sequence:
... --- -- . -.. .- -.-- .. .-- .. .-.. .-.. .-. ..- .-.. . -.-- --- ..- .- .-.. .-..
Using International Morse Code, with word breaks inserted at the appropriate points, the taps actually do spell out:
SOME DAY I WILL RULE YOU ALL
And that’s why I love FoxTrot.
Hmm … it’s clever, but a bit of a letdown once you get the translation.