Travelling in different countries has different rewards. In Germany it's the beer. In France it's the food. In Italy, of course, it's the ice cream!
But where are the best ice cream places?
One I'd heartily recommend is the gelateria on the Tiber Island. The Tiber island isn't very big and the main road crosses right over between the two bridges, and so it's pretty easy to find. They have some excellent flavours - one you don't see too often is marron glacé - and I believe they're now using organic ingredients. Very fine, and there's a nice small piazza outside the church of San Bartolomeo where you can sit down and consume your purchase.
In Siena, head straight for the Piazza del Campo, and not actually on the Campo but just off it there's a superb gelateria. One of the widest ranges of ice cream flavours I've ever seen. I'm just sad that no one seems to do an ice cream version of the famous Siene panforte. After all, chocolate, nuts, candied fruit, AND ice cream - what's not to like?
Venice is a bit poor on the ice cream front. Paulin's in Campo San Stefano is probably the best, though it doesn't have such an extensive range. To be honest, when I think of Venice I think of the 'moro' chocolate, nut and fruit cakes, or the nougat and caramelised nuts sold at the Christmas fairs.
And I never found a really good ice cream place in Florence. Pizza, yes; ice cream, no.