The best choice right now is the card that:
- has the needed connectors for your monitor
- fits in your existing computer
- doesn’t draw more power than you have available
- has no known driver problems for use cases you care about
- has as much RAM and shader processing power as possible
- doesn’t cost more than you’re willing to spend
Someone was having problems with older AMD cards and mesh distance fields in this forum a week ago.
Does that matter to you? Will the same problems show up on your machine with that card? No idea.
Personally, I’ve found AMDs to always be slightly behind the NVIDIAs in driver compatibility.
There was even a time when a new card of theirs I was testing rendered DXT compressed textures upside down compared to uncompressed textures …
If I were buying today, I’d get the GTX 1080, but it’s quite likely my constraints are different than your constraints.
Other things matter too.
Do you use SSD for your system, application, and work data drives? If not, that should be on your short list for upgrades.
Your CPU has a pretty old microarchitecture; a modern Core i7 at the same clock rate will likely run much faster (and you can get them at higher clock rates!)
Do you have two monitors? If not, spending $200 on a second monitor will give you a whole lot more area to work on, keep debuggers on, etc.