any of the 50mm are fine lens, kinda hard to mess up a 50mm prime. Advice is good here, that since you own the 5200 to stick with the G lens.
each 50 mm has some minor effects.
50mm 1.2.. brightest of the bright, a bit less soft, dreamy look ... can still buy new.. sweet
50 mm 1.4 sharp enough, nicer bokeh
50 mm 1.8 sharp sharp,, decent bokeh, cheap cheap.
50mm 2.0 really really sharp,, love this lens..
50 mm 1.8 G.. really sharp (so I hear), decent bokeh
unfortunately, only the last lens is really compatible with your 5200, that is one reason why the 7000 and 7200 is so sweet, can meter and autofocus all those old glass or older AF designs.