If you want an absolute iron-clad guarantee that you will enjoy a sumptuous stay in downtown Toronto, I highly recommend the Ritz-Carlton. The service was excellent at every level, and don't forget to check out the spa for the ultimate in relaxation after a late night out on the town...the saltwater pool is amazing, and they also have additional amenities in Clarins Spa, available as part of your stay.
The bathrooms are so luxurious and well-lit that I almost didn't want to go out. You could easily spend the night in and love every minute. The bed in our suite was incredibly comfortable and noise was not an issue. Highly recommended!