Need urgent help from old timers here!!!

I gotta buy a freaking desktop for my boss's son birthday tonight and i'm so out of time.

I have 2k in my possession now to spend for the desktop. Monitor and peripherals are already taken care of. Just the CPU unit.

Again, i need a rig recommendation and budget is 2k.

P/s: I think the ungrateful kid said to me he plays world of warcraft and cs most of the time.