Gaming with Virtualbox, has it worked for you?
Gaming in a Virtual box is a bad idea. You wont have the great 3D support that you desire and applications that require a lot of resources will lag. Some games will probably work, like minecraft and minesweeper. But running heavy programs like Battlefield, Skyrim and similar will not work.
The reason for this is that you are basically running two operating systems within each other and the one you will be emulating will be limited to a small portion of that computers resources.
A solution to this problem is dual boot. For example you have one partition with Linux (where you are all serious and stuff) and one partition with windows (for gaming). I had this setup on my laptop for several years it works great.
There are instructions in the Ubuntu installer for how you install with a dual boot setup. The easiest is to install Windows first and then install Ubuntu.
Good luck.
Personally, I have mixed results running games in Virtualbox. But I can play some of my favorites. There is a (really small) wikia site with some results about working and non-working games at http://virtualbox-gaming.wikia.com/ if you want to take a look or even post your own results.
You might want to look at something called Kainy. This is a remote desktop implementation that is specifically for gaming.
It sounds like having a Windows PC on your network to run the games might be OK, if you play the game from where you wanted. Kainy has a server for Windows, and clients for a number of OS, and game systems. They don't have a server for Linux, though.
As far as gaming on VirtualBox, I think it would be OK if VirtualBox had better graphics accelerator support. I think the emulation argument is a bit exaggerated. Windows is executing with the same processor it expects, no added expense there. VirtualBox mediates Windows hardware calls, and there may be some overhead.
The big problem is that VirtualBox is not built for gaming, supporting 3D graphics is not a priority. Nonetheless, if you have an older game that is not requiring graphics support beyond what VirtualBox has, I don't see why you wouldn't go ahead and run it there.