You don't list a motherboard in your specs (I was just wondering for suggestions)
You don't list a PSU in your specs (I was just wondering for suggestions). A nice 450w or 550w psu from Antec or Corsair would be recommended for this build.
Is your hard drive the WD 640GB Black?? (Good to go if so!!) I would look at the Samsung Spinpoint F3 500GB hard drive, as well.
1) I would look to run the 4850 on a resolution of 1680x1050 for best results. The card will run med to high settings on most games at that resolution.
2) You should be able to play Crysis on at least Med setting with good frame rates at 1680x1050
I was looking an Aloe-GL8E motherboard. Also, while looking at different things online, I noticed HP has a computer using the same CPU/GPU as I listed, but they use a 350w PSU. I'm guessing their's is too weak to run the the computer at its fullest speed (w/o OCing that is)?
athlon 620 and 4850/70 is a great combo. you should definitely overclock it, especially if you get the 4870. its easy to get over 3ghz on stock voltage with those and lots of people are getting 3.5ghz+ with modest aftermarket cpu and extra voltage
Makes two 4850 or a 4890, and there you are ready to go.
Still, the 4850 have gone high in prices, you should invest in at least a 5770. The prices are a little more affordable now, so there is not a big difference cost between two 4850 1GB and two 5770. In term of performances, it's about the same...
Athlon II X4 620
4 GB of generic DDR3 1333 (I would go with OCZ Platinum DDR3 1600, but it's your call)
OCZ Z 650W 80 plus silver
500GB Samsung F3 Spinpoint
Radeon 5850 (or a minimum of a 4890)
Sony DVD burner
Cooler Master Centurion 5 CAC-T05-UW
After thinking little, I have scrapped the crossfire motherboard and thrown the money into the graphic card. It's a little overkill with an Athlon II X4 620, but you will be able to upgrade your cpu later to a Phenom II.
I think this will suit you more. Not to forget that your PC will easily run game in 1080p... even Crysis at High settings.
Sorry for not giving more information. This will be my first homebuilt and I don't know too much about these things.
@ Redgarl, that looks like a great machine for under $1000 right there. I wasn't planning on upgrading the CPU later, so if I were to buy the Phenom II right now instead of the Athlon II, which Phenom II would suit this build best?