I don't actually subscribe to any channels, because I tend to get bored with them after a while, but a few that I've been watching lately:
http://www.youtube.com/user/Smoove7182954/videos
http://www.youtube.com/user/totalhalibut?feature=results_main
^Even though he annoys me
One I used to love watching, but she's stopped updating properly lately:
http://www.youtube.com/user/communitychannel
What about you guys?