I have never heard of Montagoli or Montagnoli Restaurant but any of the other above restaurants are excellent picks especially Gibsons and Lawry's. Lawry's menu is a bit limited with prime rib, salmon, lobster and another fish selection. I wouldn't call it a "Black tie" place. I've seen jeans and sweatshirts being served. For me however it is a "dress-up" place:
http://www.lawrysonline.com/theprimerib_chicago_gen_info.asp
Gibson's is a great restaurant on Rush St where the famous sometime dine. The menu is more varied and top notch:
http://www.gibsonssteakhouse.com/
What is not addressed above is the second part of your request...good scenery. At Gibsons you can sit outside and enjoy the street scene of wandering tourists but the others and Gibsons have great dining rooms, not known for the scenery.
2 places not mentioned come to mind for both good food and scenery: The Park Grill in Millenium Park and the Signature Room atop the John Hancock Bldg.
The Park Grill has an outdoor dining area where the buildings of lower Michigan, Grant Park, and pedestrians can be viewed. The Signature Room has the view of Chicago itself:
http://www.parkgrillchicago.com/grill/index.asp
http://www.signatureroom.com/