With old man winter being back in town and all, it might be interesting to list the best options for dining in the "underground city" network of malls and office buildings downtown which is actually pretty extensive. Here's a map from 2005:
(note that now the Eatons centre and Place Ville-Marie are now connected by a tunnel under cathcart, joining the two formerly independent parts)
So here are my nominees:
-Nudo in the Eatons centre food court: Hand-pulled noodles made to order before your eyes in a shopping mall- hard to beat in my view. Very short menu (6 or so items) all noodle-centered.
-6th floor of The Bay: as much for the ambiance of the 'Canadiana-style' dining room as for the fancy-cafeteria food specials, it makes for a fun lunch. The soups are a standout - I like the thai coconut milk/chicken soup. As for mains, they have specials like 'christmas turkey dinner' or poached salmon. Only thing is you've got to go early or else they seem to just let them stand there... I went once at 1:00 and saw a whole cooked side of salmon with dill and lemon drying out under a heat lamp...
-Café Tunnel: in the tunnel between Eaton's center and Place Ville-Marie. For me not the best coffee in town, but the best I know about within the underground city. Long waits around the end of lunchtime though.
-For a fancy wallet-busting lunch, there's always Toqué, in the CDP building (still less expensive than going there for dinner - table d'hôte starts at 25$).
I'm certain there's loads more gems down there - what are your favourites?