http://www.eurogamer.net/articles/digitalfoundry-2015-graphics-card-upgrade-guide-update-3
The best graphics card under £100 / $130: GeForce GTX 750 Ti
The best graphics card under £130 / $160: GeForce GTX 950
The best graphics card under £200 / £250: Radeon R9 380
The best graphics card under £250 / $330: Radeon R9 390
The best graphics card under £400 / $500: GTX 980
The best graphics card over £400/$500: GeForce GTX 980 Ti
The best graphics card under £100 / $130: GeForce GTX 750 Ti
The best graphics card under £130 / $160: GeForce GTX 950
The best graphics card under £200 / £250: Radeon R9 380
The best graphics card under £250 / $330: Radeon R9 390
The best graphics card under £400 / $500: GTX 980
The best graphics card over £400/$500: GeForce GTX 980 Ti