I'd note that if you're looking for a card under $150US, the 8800GT (the exact same thing as a 9800GT) is the best card you can buy, and has a price-performance ratio competitive with the 4850; there ARE nVidia cards worth buying... I was just specifying that for the most part, there weren't much of any above the $180US mark.
rockr23 :
I realize the going oppinion on this board is build your own computer and buy ATI, thats not what I'm in the market for.
I should correct you to note that the going opinions of the board tend to reflect what video cards are the best deals. And right now, in the price ranges you're largely looking at, ATi rather effectively dominates the board. Note that YES, you can use ATi cards with an nVidia chipset, (and nVidia cards with an ATi chipset) you just won't be able to use CrossFire/SLi.
Also, who are you getting this computer from? It's liable that they will charge some of their own extra markup on what card you get, so that would also affect things; that's a major reason why building your own PC is so heavily recommended: the price for getting a video card through NewEgg or another online retailer will invariably be lower than the cost of paying a PC OEM to put it in a computer they're shipping you.
Given the level of markup you listed, I'd have to say that the only option there that makes any sense to me is the 9800GT. Unless you're playing on a very high resolution (like 1920x1200 or above) it should be plenty sufficient for the likes of
Fallout 3 and
Warhammer Online. I wouldn't spend more money on more expensive cards, nor spend more money to get two cards.