I’m going to be getting a linux vps and will be using it for gaming servers, i looked around on google for the best OS for linux gaming, i saw some about a list here:
If you are getting a VPS in its own right, you won’t be able to consider Xen or OpenVZ - they are virtualisation systems, they run behind the scenes of your chosen OS.
For a game server, Centos / Ubuntu doesn’t really make much difference - I’d say whichever you are more comfortable with. Personally, I’ve used both for game servers and noticed little difference.