Nice work! The shading and the lighting look very nice.
Since I haven't watched a lot of GameGrumps, I can't really say anything about the character, but she looks very nice. Would definitely fit on a poster, and would be on a comic book. The background makes her pop out, and the white outline around her also does so as well. Her face is well drawn and her figure is very thick. But, I like that. ;D
If you were to sell this as a poster or a painting, I gotta be honest, I would buy it.