Mine has to be Steak and Ale, in South Bend. The best Prime Rib ever, and I have been to many a steakhouses. Their salad bar is off the charts as well. It is expensive, but if you ever come in for an Irish game, you must go there. They do have a dress code, but it is well worth your time. And, they have beer there!
I went to Notre Dame for a couple of years. One thing I didn't like about South Bend was their lack of cool restaurants. Chains for miles and miles. That said, I never went to Steak and Ale
Anyway, if anyone's ever in the Naperville, IL area, Timpano's in downtown is the best. Expensive-ish at night ($100 for two people), but if you go during the day it has a similar menu and you can eat for $40 for two (w/o drinks). Fantastic food. Italian. You can probably cut through the chicken Parmesan with a dull spoon
La Dulce Vita in downtown Lemont, IL is also very very good.