Musical Robotic Comedy troup Steam Powered Giraffe!
You guys have got to check these guys out. They have a whole concept and backstory behind their characters/act, and perform comedy skits between songs. They do all their production and makeup themselves, those are their natural voices, and they write some really great tunes. If the first video isn't to your musical taste, try another, or a comedy video, because these guys don't really adhere to a single style of music, nor a single era, and are an amazing and unique comedy act. They also have a web comic about their origin in the works.
Wish it would let me post more than one. D: Tell me if you want me to post more! Or just click around youtube! You won't be disappointed!
http://www.youtube.com/watch?v=dDRHx4cPgbE