Wow, well my all time favorite, most comfortable nursing shoes in this galaxy are called: Clinics. Used to be sold opposite MACY*S on 34th Street in NYC. Waaaay back in the day. Having a hard time finding anything that resembles them. They were all white, with shoelaces, made of leather, kind of resembled old fashioned nursing shoes. I still have a pair, but they are there to remind me of when I first entered nursing.
Now I wear Army boots (smile) BUT my second pair of nursing shoes would be: Clogs. The wooden kind, not the kind that you can throw in the washing machine. Kind of expensive, if I recall.
Here is one website that you could check out:
I have had many people tell me how comfortable white sneakers/tennis shoes are, but IMHO I don't think they look professional at all.
Good Luck in your search for the perfect nursing shoe.