There's a nice Rockstar sale on Steam at the moment. GTAV would be an awesome way of enjoying your new kit.
Other than that, if you want the full PC experience. Civilization 6 just came out I think. (I'm still on 5 but love it). Theres also some decent Sim games about again with Cities Skylines and it's Expansions basically being the first decent Sim City in 3D.