The historical Portofino cafe on the Piazzetta — a few tables outside, a wooden bar inside, and a steady parade of famous faces in the photo collection on the walls. Order an espresso for €5 or a Negroni for many times that. Either way, the table buys you an hour of front-row seats on the harbour.
The morning espresso is genuinely good (Lavazza, well pulled); the cocktails are competent rather than crafted. You are paying for the location and you should know it.