This computer, but with the 5570 graphics card swapped out for a 7850. Graphics card is nice, but my CPU is a tad bit underpowered. Not a big problem most of the time unless I'm trying to play Natural Selection 2, which is very CPU heavy. Got the computer for $450 on sale 1 and a half years ago.
If I were to upgrade my CPU, I'd probably need to buy a new motherboard and a new power supply too. >_>
As far as peripherals go, I got a Dell QuietKey keyboard I got for $3 at a thrift store because it's better than the shitty one that came with my PC, and a Logitech G500 mouse. i really recommend this mouse, it's great. I also have a record player that hooks into my computer via USB, that's pretty cool.