Seeing the leaning tower in person was one of the funniest things I've ever seen in real life, I can't believe how hard it made me laugh.
It was cathartic to see it and think of all the projects I've worked on in the past that were poorly run.
Also while Pisa isn't much to see you can also walk the quite long Tunnel Di Pini and it makes for quite a lovely day of picnics and nature.
Though to be fair, Florence in general is hard to beat.