In Rome, I can recommend some.
First, there are dozens of great places, but since we stayed in the Trastevere; that is where we had gelato. While it certainly can be a mid-day treat, the best is one while wandering in the evening, we preferred after dinner.
Gelateria alla Scala, just off the Piazza of the same name, does an excellent job, including some less common flavors.
Another really interesting one is Otaleg, not far from Piazza Santa Maria. Good flavors, plus many Vegan options.
My standard is Pistachio Gelato, if they can do that right, then the other flavors are usually solid. Both places did an exceptional job...though I have to say in Sicily I found some better...but Sicily and Pistachios...that would make sense.