So we tried both St. Viateur and Fairmount in our time in Montreal and both my husband and I agreed that Fairmount has the best bagel!
The experience in itself is better, you walk in surrounded by flats and flats of bagels. It's almost like a bagel maze. The staff were very friendly and watching them make the bagels while waiting was great!
We got a cinnamon raisin and sesame with cream cheese and we also got 2 plain sesame bagels for later. Both flavours were very good although everyone is right about the sesame; it's delicious! I loved the texture and the sweeter of the Montreal bagel. I only wish we lived down the street! Although maybe then I would eat too many bagels.