Avoid Milano Inn at all costs, their sauces (be it white or red) have absolutely no flavor whatsover and the consistency of wallpaper paste. But at their lunch buffet, you can eat all the goo you want! It is VERY popular with the locals, probably because of the great volume of food you can eat.
You could try Bertolini's or Bucca di Beppo, although they are chains, are pretty good American Style Italian.

Palomino's has a nice bar, varied menu, tasty food, big-city atmosphere. I heard McCormick and Schmick's is OK. Bertolini's in the Circle Center mall has predictable, but pretty good Italian food.

Some of my favorite places in Indy (I've lived in Chicago and Philadelphia before moving here 10 yr ago, love to travel to NYC and SF).
Bazbeaux pizza - on Mass Ave and Broad Ripple (Some Guys pizza in Carmel is also pretty good).
Gray's Cafeteria in Mooresville -- I used to think all Indiana food was bland and pasty until I ate here, it's just yummy home-cooking.
Asaka sushi -- on 82nd st behind Hooters, excellent sushi at a great price ($1 a piece from 5 to 7 pm weeknights), usually packed with Japanese customers.
India Sizzling on Allisonville in Fishers - only ate there twice but the food is very intensely flavored (not spicy), I like this place better than the Indian restaurant on the main drag in Broad Ripple.
Bosphorus Turkish cuisine - in a brightly painted house on East st(?), delicious Mediterranean/Middle Eastern food, tastes home-cooked
Cafe at Nordstrom (lower level) - OK pastrami on rye

Some other good places (albeit these are chains): Oceanaire, Palomino, downtown Claddagh (fish+ chips as mentioned above), PF Changs (sadly, I find this to be the best Chinese food in town and I'm Chinese), Scholars Inn, Bertolini's in Circle Centre, The Ram

Over-rated in my opinion: Mikado, Wasabi on 82nd (pricey tiny portions), Sakura (long wait for table), Rathskellar (very bland sausages, but great beer and atmosphere), Agio, Greek Islands, Cafe Patachou, Sahm's in Fishers

Truly Horrid: Milano Inn, Cici's pizza, Easley Winery