NVidia has relevant hardware for irrelevant prices, as usual. Which probably doesn't matter, since people buy it regardless. bur for pure gaming purposes, I would say the 4GB R9 380 is the minimum, with nothing in its street price range of $150-189 to compete. GTX 960 4GB is worthless, the memory bus cannot utilize more than 2GB anyway. That's the reason 950 and 960 game performance is so close - the 128bit memory bus.
So, for the three gaming segments we have: R9 380 4GB < R9 4GB 290 /yes the $220-240 street price R9 290/ < you choice of AMD Fury or GTX 980.