I'm going to second this, with a couple asterisks. $800 for the computer is probably about where you get the most bang for your buck in terms of AA/AAA gaming, but you will still need peripherals - keyboard/mouse, speakers/headset, and a monitor, that can tack another $1-200 on the price (notwithstanding that even if the controllers come with the console, you still need a TV.) Logical Increments puts their "good" tier at about $761, suitable for 1080p 60FPS with medium settings.

Arguably the bigger value here is not being locked into a platform - if you find yourself with a little more budget down the road, you can piecemeal out your old PC with newer parts for a lower cost than a new console (with the possible exception of the GPU) and you can get more utility out of a PC than a console.