Whatever my current single player game is when I want to be solo (Primal Far Cry).
Then I go back and forth from pubg and bf1 when I want to play nice with others.
Ill usually switch it up and have multiple games going at the same time
My attention span won't allow multiple games. I also don't get how people can buy multiple games and let them sit unplayed. I have a good radar for what games I think will be worth my time and buy them one at a time.