Guitar Hero isn't a measure of skill. It is a measure of reflexes. I don't count that as a game really. DDR is better since you have to time the beats and that takes skills. EBA is even better because you need timing, precision, and control.
If you want a challenge this generation, go for Trauma Center games. The DS ones are the hardest. Also, Ninja Gaiden and Fire Emblem: Radiant Dawn are hard. Or so I've been told.
Kimi wa ne tashika ni ano toki watashi no soba ni ita
Itsudatte itsudatte itsudatte
Sugu yoko de waratteita
Nakushitemo torimodosu kimi wo
I will never leave you