As a kid, I was a big fan of ThunderCats. It was pretty much a perfect storm: I loved cats, cartoons, and...uh...post-apocalyptic feline-dominated alternate realities, so the show was a no-brainer for my five-year-old self. I frankly haven't thought once about ThunderCats in something like twenty years, but was pleasantly reminded of it by this animated MAD parody. In the video, a classic TV trope (a father/son dispute over seemingly unprovable beliefs) is applied to internet memes, with genuinely hilarious results. Actually, I'll qualify that: it's hilarious if you've seen ThunderCats and you're vaguely familiar with LOL Cats, Nyan Cat, and similar recent online stuff.
See also: Quiz: Name That ThunderCat.
(Via Waxy, via @codinghorror.)