Some channel recommendations I didn't notice mentioned in this thread:
Newsbroke is a YouTube satirical political show produced by Al Jazeera Plus. Most of their videos are topical, done in the style of The Daily Show or The Colbert Report; I personally think the writing is a little better than the programs that inspired it. The host has good comedic timing and the show's well produced. They also make a few comedy sketches.
Here's all their videos:
https://www.youtube.com/channel/UCnHXmyuAUm9eBR27NMDsSzQ/videos
Randy Rainbow is a comedian that does comedy interviews with politicians using real news footage. He also does song parodies of current events using popular Broadway tunes. He still mixes these song parodies with real news footage, creating something like a comedy music video.
Here's his videos:
https://www.youtube.com/user/Tday4U/videos
Unpopular from Wicked parody song:
https://www.youtube.com/watch?v=TPg0BWvhMkA
This channel analyzes political issues and responds to the "skeptic" community. This guy was inspired by the likes of Hbomberguy and Contrapoints, I think. He's small and posts infrequently, but I think he's worth keeping an eye on. He's not there yet, but he's been getting better and better. His most recent video was good I thought, especially
the more experimental section at the end.
Lastest video, a response to No Bullshit (a far right, nutty person):
https://www.youtube.com/watch?v=8RP6C-0DLLI