I recommend Ca’ Foscari as they have excellent courses, especially in economics. Living and studying in Venice is a unique experience in itself, and the university has lots of international students from all over the world.
The programme itself provided an excellent interdisciplinary foundation in philosophy, economics and political science, which I find very useful to this day. The professors were very knowledgeable about their subjects, and most of the exams were genuinely interesting and useful.
Among the cons is the difficulty of finding accommodation (although it is easier if looking for apartments on the mainland).