Steam Play: Proton

Proton is program released by Valve. It is integrated into Steam Play to make playing Microsoft Windows games on GNU+Linux a simple  process. Proton is combined with Proton  D9VK for Direct3D 9, DXVK for Direct3D 10 and 11, and VKD3D for Direct3D 12.

A community fork known as Proton GE (GloriousEggroll) Edition is an unofficial build of Proton. It is maintained by Thomas Crider. The benefit of Proton GE over using the Valve provided official Proton is Proton GE will come with game fixes you need right away. Some patches introduced by this fork are merged with the official Proton builds provided by Valve. 

Need to know what games are working well under Proton? ProtonDB is an unofficial community website that collects and displays detailed data on how an individual got a particular game to work. It tells you what Linux distribution, kernel version, graphics card type along with driver version, and last but not least, commands for launch options. The rating scale is from "Borked" to "Platinum". 

The rating scale as written on ProtonDB

Platinum: Runs perfectly out of the box

Gold: Runs perfectly after tweaks

Silver: Runs with minor issues, but generally is playable

Bronze: Runs, but often crashes or has issues preventing from playing comfortably

Borked: Either won't start or is crucially unplayable

There’s about 100 games every month that get a Platinum rating according to ProtonDB. Platinum sets the bar high. Games with that rating just work out of the box  like native Windows 10 or macOS 10 games without requiring end-user tweaking.

The biggest problem to overcome is the anti-cheat software that's required for many multiplayer games. Valve is working on with services like Easy Anti-Cheat, but but as of this posting I honestly don't see anything with that changing soon.