@Lustig Andrei,
I liked sixtus V and the piccolomini pope, forget his papal name, for their design ability/interest (or disability if you hate goose foot street design, re sixtus). Also John XXIII, in my lifetime, but what do I know. I've also read stuff that made me reconsider the reviled Borgia pope, Alex VI - but that was just one book.
A friend, when she first stayed in italy, was a governess for the Barberini family. I know nothing about them, which is just as well, I'd probably be even more pissy. She liked the child she cared for, and of course history was not his fault.
Ah, that was Pius II.
wiki -
Pope Pius II inaugurated an unusual urban project, perhaps the first city planning exercise in modern Europe. He refurbished his home town which is now by his name called Pienza (province of Siena, Tuscany). A cathedral and palaces were built in the best style of the day to decorate the city. They survive to this day.