The third track of Dr Horrible's Sing-Along Blog's Commentary: The Musical, Ten-Dollar Solo. Main Part by Stacy Shirk... and gatecrashed by Neil Patrick Harris.
This is sort of a fan's response to Dr. Horrible. In it, the fan dressed as "Dr. Dreadful" applies to be Dr. Horrible's sidekick. Made by Mark Andrich.
A slightly drunk Jed Whedon decides to sing about his favorite foods with his fiancee. [Jed and Marissa are both co-writers of Dr. Horrible, in case people didn't know.]
The eighth track of Dr Horrible's Sing-Along Blog's Commentary: The Musical, Ninja Rope. Sung by Simon Helberg, Neil Patrick Harris, and Nathan Fillion.