I do a lot of these budget Pc builds. I didnt see if you prefered AMD of Intel. But if you go with AMd, and wants some bonus features, i would go generally recomend buying everything from amazon used, But only buy the parts that are marked as "Sold by amazon" and "Fullfilled by amazon promise" They are full warrantied used products, most are still in original packaging. They pay free shipping for RMA, and refund you same day. Now for the build, Its super cheap for amd. for under 1000 you can max BF3. As long as you're not on a giant Tv for a monitor =p. My .02 cents.
3 Tb hard drive (107.00)
AMD 8350(170)
NZXT phantom(87.00)
8 Gb 1600 mhz ram (56.00)
MSI FM2-A85XA-G65 Motherboard(99.00)
HIS H785F2G2M Radeon HD 7850 2GB video card (179.00) I was able to get 60 FPS on Bf3 maxed.
Aprieva LEd PSU 800 wat (60.00)
Windows 8 64 bit (99.00)
Siig IC sound card (39.00)
Thermal Grease (7.00)
Asus Dvd Drive (17.00)
120 Gb SSD (89.00)
Not only will this max all games on Ultra, but it also has a 15 second boot time, when OS is installed on SSD, it WIll OC to 4.5 ghz easy, as well as have a 7.9 Windows index score. Not that it really means anything, Just silly bragging rights. I would generally recomend something like this for a good casual gaming machine. Very reliable.