8800 GTX/Ultra are really ungainly. The Ultra has been the best card from the outset, but you're still paying double the price of a card that has more than 90% of the performance. They really are like big American muscle cars, the actual card is very big, it uses a lot of power and makes a lot of heat. There's a pedigree, but it comes at a premium. I'd go for broke and chose the most powerful (the GTX isn't all that great any more) if that was what I was looking at, although it must be said that for real nerd points you'd need to have multiple graphics cards.
Next on the list is the 8800 GTS. This is a bit sticky, as there's the old GTS and the new one. The old one came out with the GTX and the Ultra. The chip is referred to as G80 and I think the easy way to tell is that the memory only comes in variants of 320 MB and 640 MB. It shouldn't be too hard to tell what is the old GTS, it will be a lot cheaper. Avoid the G80 model, if this is your price range, ATi's top-end card is a screamer. In fact, most of ATi's cards are good options if you want value for money.
The new model GTS is an updated chip design called G92. nVidia made a number of tweaks to the 8800 design based on what the gamers were asking for, primarily, more bang for their bucks. G92 is made with smaller details on the chip, making it more power efficient and less hot, which means it is more stable at faster speeds. Overall, nVidia are very pleased with the new chip, saying it is their best design in 5 years.
This all sounds good, except that the GTS has a little brother, the GT. The base model GT version of G92 is extremely well priced, so much so that it almost edges the GTS out of the market.
Even more enticing (but confusing), there are mutant versions. Like I said, when they updated the Geforce 8, they made it more stable at speed, so the top companies like Gigabyte and XFX and Zotac took it upon themselves to make hotted up versions. Some of these are actually clocked faster than the 8800 Ultra and will deliver performance so close, you'll wonder why anyone paid twice the price to get one.
So to summarise a whole lot of garbage, the newer versions of Geforce 8800 are overall the pinnacle of the 8 series (with the geforce 9 coming this year) and with all versions sitting somewhere around AU$300-500/?150-250, about as much as you'd want to pay.
Save the money here.
