
Most emulators work very well with the Steam Controller 'out of the box' but there are a few that need a bit of tweaking to set up.

Sure, you have to use two UIs to launch games, but the benefits are HUGE :-) Coupled with Retroarch, this makes for a clean, consistent experience across all platforms, and no need to mess about adding hundreds of non-steam applications. This allows you to create a single Steam Controller config for BigBox that will then persist throughout ALL the games launched from BigBox, regardless of the emulator. IGNORE THIS GUIDE! I wrote this a while ago and since then I've realised the best way to play emulator games via Steam, and allow access to the Steam overlay and full Steam Controller configurations, is to RUN THE LAUNCHBOX 'BIGBOX' UI AS A NON-STEAM GAME.
