What to upgrade a GTX1050 to?

[alphadata]

At the moment I have a GTX 1050 (NOT ti) 2GB and am wondering what the best cost effective to performance upgrade would be.
At the moment I am considering maybe a 1050ti 4GB or a 1060 3GB, but am unsure which is the better option, or if there are any other options which would be effective.

Thanks for any help!

 

[zoltan.boese]

used gtx 980

http://www.tomshardware.com/reviews/gpu-hierarchy,4388.html