A nice, clean hotel only 5 minutes walk from San Marco, and for me, a room overlooking the Doges' jail cells. Friendly staff and good service. Breakfast was really good (especially for the price), with a fresh omelette each morning. One of those hotels where you just feel so pleased you happened to pick that one (on TripAdvisor of course!)
Be aware the single room is very tiny. Defintiely no room to swing even a small cat. But it's clean, and beautifully appointed. I didn't have any issues with it, but it's worth being aware of if that's important to you.