One city so far
We have been to Lucerne. That is the whole of our Switzerland, and rather than write a country guide out of other people’s research, this page says so and points you at the one place we can actually vouch for.
Lucerne turns out to be a good first Swiss city, and not only because it is pretty. It sits on a lake with boats running all over it, the old town is small enough to cross on foot, and the mountains start more or less at the edge of town. It is also unusually well connected: you can be in Milan in about three hours on a direct train, which makes it easy to put Switzerland and Italy in the same trip rather than choosing.
More will go here when we have earned it.