I’m using the RetroUSB adapters so I can use my authentic NES and SNES controllers. The NES controllers are my originals from when I was a kid, dating back to the late 80’s, and my SNES controllers are somewhat newly acquired. One was from an SNES I got at a Goodwill when I was working there a few years back and the most recent one was from last month, ordered online.

They really are fantastic adapters to use with RetroPie if you have the original controllers and not aftermarket USB knock-offs that have a history for breaking quickly or being, um, less than accurate.