Cannaregio is by far my favourite sestiere. It is much less visited by tourists, which means that it is much less hectic and spoiled. There are so many beautiful stretches of canal here, as well as some beautiful churches and squares.
The Jewish Ghetto is one of the most tranquil and peaceful areas of the city, and it's hard to imagine that the massively touristy areas of Rialto and San Marco are not very far away. From here you can easily travel to the islands of Murano, Burano and Torcello, and it is extremely well connected to the rest of the city, whilst still maintaining a completely different atmosphere from other parts of the city.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC.