Top games by current player count
Current Players Peak Today   Game
 
858,030 1,127,317   Dota 2
657,283 657,283   Counter-Strike: Global Offensive
131,591 131,591   XCOM 2
76,896 78,260   Team Fortress 2
74,670 74,670   Football Manager 2016
73,232 73,232   Sid Meier's Civilization V
64,842 64,842   Garry's Mod
62,358 62,358   ARK: Survival Evolved
61,467 61,467   Rust
61,016 61,016   Fallout 4

Steam Hardware & Software Survey
Steam Stats