Obviously, you need to watch Dr Horrible's Sing-Along Blog!
Here's the obligatory wikilink: http://en.wikipedia.org/wiki/Dr._Horrib ... Along_Blog
The official link: http://www.drhorrible.com/
It's a hilarious, yet touching, musical tragicomedy about a wannabe supervillain (Dr Horrible) who wants to be accepted into the supreme guild of supervillains, Evil League of Evil. (Corny, I know). "Disguising" himself as an ordinary guy called Billy, he takes his laundry to the laundromat, and there falls in love with Penny, a generous girl who volunteers for the homeless. Penny, of course, doesn't know that Billy is actually Dr Horrible (and he doesn't want her to know). Completing the love triangle is Captain Hammer, a strong but completely arrogant and selfish anti-villain who has bullied the hapless Dr Horrible for years.
Directed by Joss Whedon (Buffy, Firefly, Glee). Starring Neil Patrick Harris, Felicia Day, Nathan Fillion and Simon Helberg. The show was created during the Writers' Strike of 2008 and distributed on the internet only. So check it out.
Oh, and Bad Horse? He's... well... you'll see.