La Casa del Habanos on Sherbrook Street-great selection (at Canadian prices-ouch!!!) and an unbelievable lounge for smoking your favorite stick. Leather chairs, wood walls, great ambiance!!! Enjoy and if you have time, and your wife is not with you, chech out "chez Paris", the best of the "Canadian Ballet"
ditto mcgoospot's suggestion... lcdh in montreal is a great place to smoke- huge leather chairs and free cubita coffee. you can get decent smaller cigars for around $15- i didn't see any aged stuff tho. the lcdh is just a few shops west of the ritz-carlton so it's easy to find. have fun.