It is not easy to find a nice Italy restaurant in Mestre for a reasonable price but Columbus is there!
We went there last week, a party of 11 for a 4 days visit of Venice but stayed in Mestre (no need to park a car and cheaper hotels). We looked for a 'not too touristic' place and found the Columbus (which was also recommended by the hotel). It says Pizzeria but it offer a varied menu on top of the pizzas. All 11 guests really enjoyed the place and food, the menu was varied enough to fit everyone. The "zuppa de cozze" was gorgeous, the pizzas with a real thin crust baked in a wood oven and the "salatone" very fresh. The portions are very generous and the staff was extremely welcoming and accommodating. The 'coperto" (bread cover) is 2 Euros per person - pretty average and they don't rip you off with a 10% added to the bill (as we experienced in Venice - without any mention of this on the menu). The price are extremely fair for the quality of the food and especially in light of the prices charged in restaurants in Venice. We warmly recommend the place.