Possibly the most evil cartoon series on the planet.
The show about Ricky Ray!
Animated sketch and improv comedy from a group of L.A. comedians!
When you beat Portal you're treated to this song. It's called "Still Alive" by Jonathan Coulton (http://www.jonathancoult on.com/). Loved it so much I made it into a video. Enjoy!
Edit: Added in music credits. Thanks!