R9 380x 4gb edition you can also get the older R9 290 still. and a 4gb AMD card will have actual 4GB of VRAM and enough memory bus to support it, unlike Nvidia's 900 series offerings below the 980(which is a comperatively garbage card if you can afford the extra for the 980ti). amd can get driver updates any time they want the newest release. nvidia will only let you do that once every 3 months unless you sign up for a spammy premium club to unlock the already free drivers. nvidia also uses drivers to gimp the titans out of double-point computing so you can't use them for their full potential. they're both equal if you accept the spyware tragedy that is windows 10.

Bang for buck= some AMD card However Nvidia cards are quality stuff, definitely worth the premium imo You should try and get the 970, or save until you get it

Gtx titan x. Future proof as -blam!- super expensive but you won't have to worry about swapping it out for a while.

As an AMD fanboy, I'd say the R9 380X or the 270X which can be purchased for as low as 120$. As for nVidia, the GTX 960 is excellent for its price.