Looking at the absurd amount of complaints I've seen towards nVidia's (lack of) driver efforts on Kepler cards, I'd stay away from cards of that gen as much as I could.
I'd definitely go either for a GTX960 or a R9 285, if you're limited to $200 or less.
The GTX 960 will run Witcher 3 better than its AMD counterpart.
Within a week, AMD is going to re-launch the R9 285 as R9 380 and that might come with a better optimized PCB.
If you're not willing to spend more than $150, definitely go with a 2GB Pitcairn (R9 270, soon to be re-launched as R7 370). It's a much better performing card than the GTX 750 Ti.