For those who just started thinking about buying graphic cards especially for mining.
In crypto mining beside ASIC machines you are able to see that somebody always use one or bunch of them for mining.
List of popular and recommended mining graphic cards:
Radeon RX 460 4GB
Radeon RX 560 4GB
Radeon RX 470 4GB
Radeon RX 570 4GB
Radeon RX 580 8GB
Radeon R9 380 4GB
Radeon R9 380X 4GB
Radeon R9 Nano 4GB
Radeon R9 Fury 4GB
Radeon R9 390 8GB
Radeon R9 390X 8GB
Radeon Vega 56 8GB
Radeon Vega 64 8GB
GeForce GTX 1050 2GB
GeForce GTX 1050Ti 4GB
GeForce GTX 1060 3GB
GeForce GTX 1060 6GB
GeForce GTX 1070 8GB
GeForce GTX 1070Ti 8GB
GeForce GTX 1080 8GB
GeForce GTX 1080Ti 11GB
Nvidia Titan XP 12GB
Remember about this list when you will try to buy something for mining in the future.