I have been meaning to upgrade my graphics card from my MSI Geforce 210. Luckily today was my birthday so I got a lot of money. I was thinking about spending some of it on an ATI Radeon HD 5770 with at least 1 gig of VRAM but I am also looking at a Nvidia gtx 460. I would mostly use it for Gaming. I am currently looking to spend up to 200$. Right now my current specs are:
If you're looking to spend 200 then get the GTX 460 768 version, its significantly better then the 5770 (its more comparible with the 5830 and even then is still better than), and overclocks very well.
You can get a 5770 for like a 140 dollars, so its not really a good comparison.
I agree with helltech in this matter, Although if you choose to sell off you 210 before you buy your card you should be able to afford a MSi 460 Cyclone 1GB or similar which is worth the extra money invested.
Oh, I forgot to mention that sometimes theres a issue in certain case with the MSi Cyclone 460 1GB in SLi because of its large after-market heatsink and fan. However if you dont intend to SLi and/or you can confirm that your case has the required clearance in all the appropriate slots it will be perfect for you.
Also tom's hardware just had a article posted on the best GTX 460's(were I sourced some of my info from) that I recommend you review, Its on the home page atm.