A must stop for coffee lovers.  It simply the best, richly flavored with a thick crema on top.  It comes automatically with sugar so specify “senza zucchero,” without sugar, if you prefer it plain.  There are also pastries and chocolates to accompany the coffee and lots of treats to take home.  There are two Sant’ Eustachhio cafes in the square; this is the one that doesn’t look so fancy.