#Christkindlesmarkt in Nürnberg is really crowded. If you want to go there anyway, go between Monday and Thursday. There's an international corner that's a bit more diverse and usually less crowded.
If you're quick and lucky, you can get a "Glühweihnfahrt" in a historical tram.
https://www.sfnbg.de/index.php/en/tram-rides/gluehwein-tours
#Dinkelsbühl and #Rothenburg in the region have historical city cores and prettier Christmas markets than #Nürnberg. The medieval one in #Fürth is pretty nice as well!