Minecraft perhaps? Modded ones like technic, feed the beast etc, there are lots of custom servers for those around the globe and ping across different reigons isnt too bad if you decide to region hop.
Theres also space engineers and starmade if your more spaceship inclined.
ARK survival, rust, etc for the survival types.
Unturned if you want something survival for free. (Suprisingly technical modded minecraft servers have better/less toxic player bases than most other survival games; the amount of players who just go around killing for the sake of killing, griefing and screaming insults and racial slurs/allauakbar can be too damn high.)
I'm not too sure for custom servers for FPSes though.