This is probably the best grocery store in Toronto. Fantastic aesthetic presentation, a variety of well-prepared gourmet foods, and knowledgeable staff.
One of my favourite places in the world is the Food Hall in the London landmark Harrod's, and this is as close as it gets in Toronto. There's a fantastic selection of cheeses, a caviar bar, and a European-style Pâtisserie.
There's also a gelato bar by the exit onto Carlton - and it's fantastic. $2.99 for a large scoop of gelato, which is far cheaper than anywhere else in the city, and the quality is comparable to anywhere you'll find this side of the Atlantic.