I think my graphics card might be getting a bit dated. It seems like it's crashing more and more while playing intensive games and I know the card is almost 2 years old which is ancient by gaming standards.
I am looking to spend $100 - $200 and preferably nVidia.
Although you may prefer Nvidia, frankly they are not very competitive right now in the $140-$200 range. ATI's new 5xxx-series cards are more power efficient, have DirectX 11 and are cheaper. The GTS 250 is a good value at $115--but is not that big of an upgrade over what you currently have.
The 8800GT is still a decent card. If it is crashing during games I would first make sure it isn't dusty. Remove the card, take an air compressor (not canned air it's weak) and blow it out really well. I would actually do this to my Whole PC. I do this once every 6 months, at least. Dust = Enemy
If you are looking for a nice leap from a 8800GT I would look at a 4890 or GTX275. However, since the 275 is about $250-$300 that is out of the question. a 4890 will run $200. HOWEVER, I did a little looking and saw the Gigabyte 260 OCed version for a good price on Newegg. It's factory overclocked and will give you the performance of a GTX275. So this is my recommendation.
That's the only one under $200 on newegg, my friend got an EVGA one once before for around $170 but prices have risen.
If I had to upgrade from an 8800 I'd probably get a 4890 or 5770 if I needed to remain under $200, though. The 4870 performs very well, and mine has been going strong for the past few months, even with everything I've put it though.
I'm still not a total fan of the 5750/5770 cards when you are looking for raw gaming power. They are great if you have a power supply that won't handle a higher end card, but if you can take a GTX260 OC or 4890 for the just under the $200 mark there just is nothing in there that is DX11. I really wish ATI had something to fill in between the 5770 and the 5850, but they do not.
Maybe when Nvidia FINALLY gets their new cards out they will have something to offer. Whenever that will be. I'm still waiting.