The Ultimate Guide To RetroPie Controllers – Fun Consumer Tech
Amazon.com: 2 Pack 2.4 GHz Wireless USB Controller Compatible with SNES Games, SAFFUN SNES Retro USB PC Super Classic Controller for Windows PC MAC Linux Genesis Raspberry Pi Retropie (Multicolored Keys) :
How to use a PS4 controller on Retropie? (the easy way) – RaspberryTips