We usually do a bus tour when we travel as of late. They are touristy but they do give a decent general over view of the city. Bus tours are what they are.
The Gray Line Montreal tour is a 2 hour tour. There are 8 stops and a bus comes about every 30 minutes. The cost is $50.00 per person which is not inexpensive. However, this is for 2 days and that enables people to go back the next day to see some destinations in more detail.
The bus stopped at Notre Dame, Old City, The Latin Quarter, St. Josephs, Mount Royal, The Plateau, etc, Gray Line has the open air double deck bus and one standard bus with A/C and a bathroom.
The tour was given in English and French, some guides were better then others. The people at the stops were all very friendly.