I have mentioned a few times how I originally started playing GH1 back in the day on controller. My buddy who introduced me to the game right before GH2 came out only had 1 guitar so we would play together, him on guitar and me on controller. Seems after all these years I still kinda got it, but definitely can't play the songs I used to be able to. My best FC ever was Cliffs Of Dover on GH3 but I could never/will never get that again.
I personally feel like the Dualshock 2 was the best controller to play GH with as it doesnt have deep travel triggers like all controllers after but my Halo 360 Special Edition controller does the trick.