It really depends on what games you play, what resolution/graphics settings you want to play them at and at what refresh rate.
In more recent CPU heavy titles you'll see a CPU bottleneck anyway, restricting your frame-rate regardless of your GPU choice.
So unless you are going to upgrade your CPU anytime soon, I'd go for a 1050Ti for 1080p gaming at 60Hz (for example). With a card like that you'll probably not need to upgrade your PSU either.
With a more powerful CPU such as an i5, well that opens up the door to something like a 970 of course.