The three icon sets are nice, but they feel kinda limited. It'd be nice to have more sets like:
-Nintendo Switch (Current Default Looks Like Mix Of Switch And Xbox Or Android Controller)
-Xbox One (Current Xbox Icon Set Is 360)
-PS3 (Select And Start Instead Of Options And Touchpad)
-Steam Controller (More Of A Personal Preference)

also, maybe a gamecube controller icon set for the fun of it too? it has enough buttons.

proposed change for the switch icons

I'd give the plus and minus a circular button, just like the rest, since it makes more sense for pro controllers.

I made the icon sets as best as i could, and even made the gamecube icon set for the fun of it, only things i had trouble with were the guide buttons for xbox one and steam, the ps3 start button, the left touchpad as a dpad for steam controller, and that's about it.
Edit: the triggers for the xbox one set need another look, they don't look great as just a recolour. and gamecube icons are gonna be weird just because the letters are just darker colours of the buttons. adjusted some things as well as added a set for nintendo switch gamecube style controllers

Are you able to provide a list of the icon set names in order of the graphic?

List from top is:
-Default
-PS4
-Xbox 360
-Xbox One
-Nintendo Switch
-PS3
-Steam Controller
-Gamecube
-NS GCN Style (Nintendo Switch Gamecube Style)
I'm Making a New Nintendo 3ds icon set right now, using the controls from 3ds controller plus vigem (https://github.com/Eveldee/Eveldee.3DSCPlusViGEm) since it has a nice template for controls (one of the configs sets thumbstick click to left and right on the touchscreen with guide in the middle)

3DS icons added (At the end, Touchscreen Left and Touchscreen Right icons added
(deleted set, use edited one)
Edit: Fixed RT and LT for Xbox One Set and Made 3ds ZL and ZR look more round

one possible issue with any of these icon sets are wrong position on the nintendo ones, would be best fixed with a "Flip A and B" and "Flip X and Y" option.

I am most likely not going to include the Gamecube controller since it's missing buttons. If anyone has the controller, does it actually work?

Also the 3DS is a little too niche to include officially, maybe in the future I can add support to add custom icons.

I released new sets in 0.13.0

i used a gamecube controller with minecraft for switch, it works but only barely (change the inputs a fair bit)