Valve programmer Pierre-Loup Griffais and engineer Steve Cardinali talked to Tom's Hardware about the Steam Controller, it's deep-dive learning experience, and why you really need to play games through Steam to get the best experience.
Valve's Steam Controller ($99) is vastly customizable, comfortable, and has a ton of input options. You probably don't strictly need it, but you can make it your own.
A Redditor who lost their right arm in an accident decided to prototype and build their own single-handed controller to get back into gaming. This peripheral combines a mouse and keypad into a single ergonomic device for one-handed use of PCs and consoles.