As in the places where quality is a must, the simplest thing is always the one that tell's you the…read moredifference: try the standard toast (ham and cheese) and think if you ever had something as good as this.
A good choice are also the little snacks, like prosciutto with caprino, that give you the possibility to taste more without eating or paying too much.
Cost is really the only problem, of these places.
There is also beer on draught, but, as almost everywhere in Itay, it's much more expensive than Germany or UK (on the other hand, bottled water, as everywhere in Italy, is not a luxury item, but a commodity, 1 Euro, not 3 or 4 for a Bottle)
LAst, end with an espresso: you will get a fantastic little ice cream (Bocconcino of Dai Dai), to finish your lunch, dinner or snack with an additional smile.