I've stayed in many hotels in downtown Toronto, and the Marriott Eaton Centre is now my favourite.
Beautiful, spacious lobby. Efficient, helpful, knowledgeable and courteous check-in. Large, spotless and comfortable room. Request a corner room in a higher floor (ending in 02)!
Fantastic location adjacent to the Eaton Centre, Yonge Dundas Square, City Hall, and Chinatown. Walking distance to most everything else in downtown Toronto, and only steps to the subway.