I do not have any plans in upgrading to W7 anytime soon. All my pc's/laptops in the house are win XP, except for the wife's Netbook. I don't game like I used to which is why I am debating a cheap video upgrade. I'm currently running at 1440x900 and do not expect to run any higher in the near future. One of my 7600GT's died so I'm really looking to upgrade the video in the cheapest form possible. I've also thought of a single 9800GT for $95 also. Just trying to squeeze all the juice out of the turnip.
You don't mention what CPU you are running so I'm assuming that it would be able to handle a single 260 at least, which is still the way I would go even if you don't wish to move to W7 simply because it's a bit newer than the 9800 if nothing else and if you are still on XP the option to run Vista with some real horsepower in the graphic department is always open.
I'd chance an arm on the 260 and just turn up all the eye candy, up to eleven and break the knobs off. Sli on that board is pointless (now, with current cards), I had serious CPU bottleneck issues when I put a pair of 8800GT's on a 3800 x2 @ 2.6ghz.
I'd steer clear of the recertified card, it only has a one year warranty.
I would not advise using the twin 9600 setup. Even now, not every game will benefit from SLI, although most do, but I'd still prefer a single card over two low/medium end cards, it's more consistant and easier to manage.
Which of the others is a matter of personal choice: The 9800GT is the closest match to the CPU and still a fine card but it'll lack the horsepower to use max settings with AA in more demanding titles.
The 9800GTX would be my choice: It's a little cheaper than the GTX260 and has enough power to run AA/AF and high graphic settings in demanding games.
The GTX260 has the advantage of being able to apply high AA/AF AND run PhysX without suffering too much framerate loss: All those features are done by the card itself and will not be effected by the 'fairly' slow CPU. If yopu want PhysX and all the bells and whistles and enough power to have silken framerates in even demanding titles (CPU limitations asaide) then the GTX260 is the card for you.
BTW, which motherboard do you have? Have you considered a CPU upgrade?
^ Given your requirements, that seems like a good choice.
As a matter of interest, the motherboard supports quite a few of the newer AM2+ processors, so you may wish to consider a CPU upgrade in the future, rather than a whole new setup:
Are you trying to run the latest and greatest games @ highest settings or are you just trying to get your system back up and running optimally to play games you already have that are mediocre in hardware demand?
If you are trying to play the latest and greatest games then go with a GTX 200 series card such as the 250 or 260. They run cooler and run circles around the 8/9 series single cards.
If you are playing older lower performance demanding games then I would feel safe to say that I would get 1 9600GT and stash the cash for the 2nd card you were going to buy and save it for the next major upgrade such as a new processor and a much better video card once the directx11 cards come out (and windows 7 of course).
If you have to have dual cards the 9600GT is not a bad choice for fairly decent game play.
How much longer are you trying to make this system last under what intentions of game titles you plan on playing?...
Bought the GTS250. I just don't game that much anymore so a new system is not cost effective. Trying to stretch every little bit out of this system without spending much money. Thanks for the input all.