Obviously the musical knowledge required to play a guitar far exceeds the mimicry that is Guitar Hero - but as far as just plain dexterity goes you gotta give some credit to those crazy Guitar Hero kids. Heck, certain songs are way harder on Guitar Hero than they are on a real guitar - Weezer’s My Name is Jonas comes to mind. The intro is easy on a real guitar, but on expert in GH it’s significantly more interesting.
Dude, Malmsteen might be a huge jerk with bad hair and an ego the size of Maine, and I’m not a fan of his music either, but he’s undeniably a ridiculously great guitarist. (Unfortunately.)
*edit:
*Also, I can’t find quite the proper YouTube clip, but **Leo Kottke **is an *amazing *fingerpicker. I’m a big fan of rock guitarists and all, but I think that for overall difficulty stuff like this takes the cake. 
