Anyways, I have a Gigabyte MA790GPT-UD3H mobo with a 650 watt PSU. Looking to replace with a nvidia, as my experience with radeon has not been positive. Also, looking to stay within the $100-200 range or below.
As you can see by the chart the 5850 is a pretty decent card and is high up on the chart , so in sticking with a $100 to $200 budget range would mean going with a minimum one level higher upgrade with a new video card. Is that something you want to do?
The GTX 560Ti is one level above what you have now and would be considered a miminal upgrade. The othe card in that level is the 6950 from AMD and is more expensive and some of the others are hard to find or you can't find them at all. If you went with the less expensive GTX 560 then you are doing a downgrade and the same with the 6870. So you can either increase your budget or think about going with the 560Ti.
Sorry, I should have clarified that I just want an alternative to a radeon HD 5850, whatever price it is. I just assumed that an alternative would have cost around the $100-200 range. Under a $100 would be great too.
I would go with the 550Ti as that will at least give you the option of some gaming along with whatever slse you will be doing with the computer. As far as other cards you can go all the way down to $20 for a card but the performance keeps decreasing as you go lower. So the 550Ti sits right at about $100 and would be a good choice as an alternative to what you have now even though it's a downgrade.