Okay, maybe it's not the "ultimate" sit-in restaurant, but it's a really really good one.
Another reviewer basically covered all the great things about Macaroni Grill down pat, but I also want to say that for a sit-in restaurant with the kind of service and environment it has, their prices are pretty good. My dad still thinks Macaroni Grill is expensive but then again, he thinks $5 shirts are expensive. Go figure.
The majority of the menu is below $10 (which is quite rare for sit-in restaurant these days) and the meals are HUGE!!! My mother and sister-in-law shared a salad 50-50 and still couldn't quite finish it. I'm a pig and I ate my whole dish PLUS dessert (oh god). But I was really hungry! And the food is just TOO good. The waitresses and waiters were awesome, the only thing about the service I'd ever complain about if I had nothing better to do is that nobody seemed to see us when we walked into the restaurant -- that was because there were only two waitresses in the restaurant at the time (eheh). So yeah, no biggie. =)
Another thing, I gave 4 stars rather than 5 because the food took a particularly long time to be cooked. =/ But if you bring a friend, the time flies by =)