As of today, Windows is the only serious gaming OS. Valve are working on a free SteamOS, which is linux based, but it will be years until you can really get a significant portion of the games you want on that. Regardless, except for console exclusives, Windows plays and will continue to play all games.
So, if you want to game, Windows 10 is your only good choice, albeit not free.
EDIT: In case you didn;t infer from what i wrote, what makes an OS bad for gaming is that games do not get released for it. Now, tehre are a hadful of games that get released on Linux. but no serious gamer would get satisfied by that.