I really,
really love lonlonjp's channel [http://www.youtube.com/user/lonlonjp/featured]. Seriously. In a non-healthy way. He's just far too amazing. He does some of the best fingerstyle remixes of video game and anime songs I've ever heard.
Even better, his collaborations with Laura Shigihara [http://www.youtube.com/user/supershigi?annotation_id=annotation_929697&src_vid=a7SbdRV0YOc&feature=iv] (as in, the
Plants vs Zombies Laura Shigihara), which are just beautiful.
A great team I love from YouTube has to be the Key of Awesome [http://www.youtube.com/show/keyofawesome?s=1] guys, who make some pretty sweet song parodies, as well as some decent originals.
Oh. I'd almost forgotten about this man. Igor Presnyakov [http://www.youtube.com/user/Iggypres?feature=g-u-u]. Holy crap this man can play guitar. A fantastic fingerstyle guitarist, he usually plays a rhythm line, a lead line and percussion on the guitar body all at once, sometimes while singing. Definitely worth a listen, and support.