go with the first one, it will give you some extra breathing room incase you want to put in an extra HDD or another DVD drive later. Or just plain upgrade your PC again.

your good either way

Ok I used an online PSU calculator and taking into account 4 sticks of ram 20% capacitor aging 2 hard drives 5 usb devices your CPU and either the 4850 or the 9800gtx you're good either way. 342 watts recommened.

Questions now - how much you wanna spend and whether or not you have decent airflow into your case - if not get a dual slot graphics card, if so the bang for buck of the 4850 is where you want to be IMO. xD

I sent a reply to your message, and I have one to three usb devises(flash drives) and one usb keyboard and mouse combo

4850 is approximately equal in performance depending on game, but can be found cheaper ($150-$170) despite them having the same MSRP ($199).

well considering the GTX+ isnt even out yet lets wait till we see any special deals

The MSRP of the GTX+ is supposed to be $230 when it was announced.  The 4850 is now hitting $155 with rebates so there'll have to be some massive discounts to be comparable.

The 4850 will also only get better performance as they improve the drivers while the GTX is already a very mature driver.

You guys need to remember that Nvidia is going to drop some hot new drivers. CUDA will make Nvidia cards run way better than ATI, and I expect them to be able to run ray-tracing once lazy devs take advantage of it.

I know all of this because I'm on an NDA, but I cant disclose performance numbers to you kiddies.

Its clear as ice that the 4850 is the best bang for buck card under $200. Just get it and be happy with it.