The gtx 980 is the best you can get, but I would personally prefer the r9 390x because it has almost the same performance but cheaper, and most IMPORTANTLY IT HAS 8 GB OF VRAM! so it's more future proof , but don't worry the gtx 980 will last a couple of years, but I personally prefer the r9 390x http://www.newegg.com/Product/Product.aspx?Item=N82E16814202147
What resolution do you plan on gaming at? The Gtx970 is quite a bit cheaper, yet performance wise it is not far away from the Gtx980. The gap in performance closes when the Gtx970 is overclocked. It has a great value for the money it costs.
Check out the benchmarks: http://www.tomshardware.com/reviews/nvidia-geforce-gtx-980-970-maxwell,3941-8.html