If your gaming at 1080p I'd take the 480 over the 3gb 1060. I have a 780 3gb and at 1080p have found 3 games that use all 3gb and cause stuttering. It's easy to fix by dropping settings but 3gb is clearly a limiting factor at 1080p in some modern games and this will most likely only get worse.
Just in the stages of planning my next upgrade but its delayed while I get a new car.