No, I don't play games for a living...well war games maybe...
I am a DoD contractor and a network engineer. Without getting into juicy details, my job involves writing programs in LabView and being the graphical environment that it is we use 30" monitors to make it easier to lay everything out which requires a healthy video card to drive it.
When I'm not doing that I'm testing programs and running several VM's locally on my machine as part of the development process - so it needs a healthy dose of horsepower to do all that as well...
And we're all pretty technically inclined and we know what we need for processing power, etc... so we get to build our own workstations..