I'll also add other things that make me laugh starting with each letter.
Letter C is for Chariots of Fire, which follows the running theme.
Other things that start with C that make me laugh:
C is for this guy (well, somebody cosplaying the guy) who laments his Cabbages on Avatar: The Last Airbender. One of my favorite ongoing jokes.
C is for cactus-wielding rioters.
C is for hitting C and CE a bunch of times of my calculator.
C is for stalker Cameras.
C is for Camouflaged dogs.
C is for Capes, and how women are superheroes and they should all wear one.
C is for Chatting about Cat facts.
C is for Chewbacca, everybody's favorite giant teddy bear.
C is for the Force Choke.
C is for the Cone of Shame.
C is for Congress.
C is for the potential pitfalls of continually Correcting grammar.
C is for the brainiacs who can Count all the way to potato.
C is for all the cool Crazy people out there. You're my kind of people!
C is for Ctrl-Alt-Delete.
C is for Curiosity and those who really, REALLY need to figure out everything.
C is for Camouflaged Cats.
C is for Chocolate and how everybody loves it.
C is for the Credible Hulk.