Here’s a good writeup at NikonRumors.com about the many lens choices available for a 50mm prime for Nikon cameras.
I didn’t study every chart, it’s a little much, but it’s interesting how many criteria determine the quality of a lens.
I have a Nikon 50mm 1.4 and love it, it’s a great lens. It’s probably my second most used lens. It focuses well, works great in low light, is sharp, has wonderful bokeh, and is nice and small. For my purposes, there’s no need to switch to anything else that has slightly more X or Y.