Freiburg Germany or Basel Switzerland

They are both unique and different. What would you like to see? How are you travelling? Where will you have been previously? How long will you have?

I preferred Freiburg over Basel although the market at Freiburg was in full swing so that made the central square more interesting.

I think we have to know the time of year and the approximate length of the stay. For example, would you have time actually visiting the Black Forest? Do you like museums? Is this exclusively by train? Have you visited Germany or Switzerland before? Where are you before Freiburg or Basel?

I now see this question has been asked twice by the OP.

https://community.ricksteves.com/travel-forum/germany/germany-switzerland-045e2da4-be4e-49ab-8666-535a14797db5