http://www.pcgamer.com/steam-reveals-2017s-biggest-earners-including-the-witcher-3-h1z1-and-pubg/

Steam has released its annual list of the highest-earning games of the year, and it includes one or two surprises. Among the 12 games that generated the most revenue sits Ghost Recon Wildlands, for example, which I wouldn't have expected. The overall biggest earners also include evergreen titles not released this year, such as The Witcher 3, Rocket League and Counter Striker: Global Offensive. 

To compile the list, Valve looked at game sales, in-game transactions, and DLC. It took the top 100 (the full list is here) and split them into tiers: platinum for the top 12, gold for the next group, and so on. That means there's no actual ranking—we just know roughly where each game placed. The top 12 earners, in full, were: