Valve recently released the Steam Machine - a SteamOS device in a desktop/console form factor. It's fairly pricey (probably mainly due to global supply chain is...
What about steam controller running in windows? I'm having a hard time getting it setup to work with testing my game, I had to go back to a standard Xbox controller.
I think it depends on the availability of a Windows driver for the Steam Controller - I'm not sure there is one at the moment, and Valve might not be interested in making one if they only want their hardware to work with official Steam games.