DarkHarsher :
The best GPU playing 1080p, max settings, and newer games like Batman Arkham Knight, COD Black Ops 3, Just Cause 3, Rise of the Tomb Raider, Tom Clancy's Division, and others. I want a GPU that can do all of that for 2-4 years without upgrading. I was thinking the R9 390x would do it because it has more VRAM then the 980 or the 970.
The GTX 980 does better than the R9 390X in almost every aspect even if it has a bit less VRAM.
For 1080P 2 GB is sufficient currently, however i predict it will use up to 4 GB in the future.
I would say either go for a Tier 1 GTX 970 and overclock it. That will last you a couple of years even on near max settings.
However if you do not mind spending more the GTX 980 is also an excellent choice, if you want something in between the R9 390X is also great.