Sofitel is best option on Sherbrooke Street..... St James is the best for Old Montreal, but limited choices with two beds for people who want to share a room. Nelligan and Place D'Armes are very similar and more than fine. I personally would take saint sulpice with a room facing the garden, but again, limited two bed options besides a sofa bed.
St. Paul is really showing its age and would not come on my list.
In Quebec City, Auberge St Antoine with its new GM is my personal fav