I've recently been looking into it quite a bit. What I've come up with is the i5 750 CPU, ASUS P7H57D-V EVO Motherboard, you'll want probably 6GB RAM, and I was considering the Radeon 5850 video card although you can get cheaper. All this is just over $1000 CDN, but that's reusing my old case and HDD as well. From scratch you'll have to add another few hundred for a case, a monitor, HDD, DVD, mouse and keyboard. This system tho, from my research, is an "upper class" system especially if you overclock. It's not the best, but it's quite good.