Try Oliverio's on Derby Road - they have very good Italian food and a nice atmosphere. Pasta entrees are $10 to $18, with steaks and other meat dishes being a bit more. If you plan ahead with the owner, they have a reasonable family style option - for approximately $20 per person, you can pick a soup/salad, a pasta, a meat dish, a vegetable, and a dessert. I hosted a dinner there a few months back for a large group of picky eaters, and everyone was very happy with their meal.
Other options include La Dolce Vita and Stonecutters, both of which are in downtown Lemont.