Data to the rescue! A streaming guide called Reelgood has put together a list of options you might like, pulled from a variety of different platforms, based on the viewing habits of people who enjoyed spending time with Geralt of Rivia. The aforementioned Mandalorian is there. So are several other series based on books, just like The Witcher, including Good Omens and American Gods: both of those come from the brilliant mind of Neil Gaiman. There's Legion if you're into Marvel movies and Merlin if you're fascinated by the legend of King Arthur. And more!