There are lots of castles in Emilia-Romagna we could get to in our rental van from Bologna between Christmas and New Year's Eve, but I'd like to find one that will be open during that holiday week, is as medieval/early Renaissance as possible, has some painted walls and some period furnishings like the Palazzo Davanzati in Florence does, and can be visited without a tour or guide.
The kids are probably expecting a Gothic and Disney-esque castle and that's not what Italian castles are like, but it should look as much "like a castle" as possible. They are 6 and 9, but it will probably be me who will get impatient with a too-slow or too-fast guided tour.
Torrechiara near Parma is pretty much perfect except that my husband and I already spent a whole day there a few years ago.
Here's some contenders I found online, but I'm hoping for some recommendations and other possibilities from people who have visited castles within 1.5 hours of Bologna:
Rocchetta Mattei (NOT medieval, but pleasantly quirky)
Rocca Sanvitale (have to be on a guided tour?)
Castello di Vigoleno (some parts can be visited, others are a hotel)
Rocca Sforzesca Imola (not much inside?)
Castello Estense in Ferrara (nice because we could take the train from Bologna)
Ricky from Modena posted here a year ago that his favorite castles/fortresses were Vignola, Fontanellato, Torrechiara, Carpi, San Leo, Ferrara, Vigoleno, Rivalta, Castell'Arquato.