60
Two d-pads, one analog stick, three triggers and two face buttons? What were they smoking in Kyoto in the early 90s 
I have only seen a Nintendo 64 in real life like twice back in the 90s so I have no clue what all these buttons do in most games.
Thanks to recent developments I went and downloaded every Nintendo emulator I could. I was surprised to see how fractured Nintendo 64 emulation seems to still be on PC. I was expecting there to be a Duckstation, PCSX2 or Dolphin equivalent but no, there seems to be no clear winner, and two of the bigger ones are closed source and use plugins like it's 2005, and one doesn't even come with a GUI by default
GC controller was obviously designed with children in mind (especially abxy), but as I discovered from teaching a lot of things designed for children are also the best design for adults. Each button and stick is extremely distinct and has its own clear shape and colour, making it easily found by sight or touch, and they're all nice and squishy so you can clearly feel the presses.
My only gripe is that you can't use them for more games.
Gamecube controller design is great. You never look at it and wonder which button to press. There is very clearly a "good button"