Montreal is nice. Best to have your hotel in (or walkable to) the old quarter, though they more pricey. Bagels are amazing, and they have their own amazing pastrami ("smoked meat"). Walk up Mount Royal; it's a lovely park. I really love Quebec City, too, if you can swing part of your trip up there. I had a breakfast I will never forget in Quebec City, but would have to look up the name of the place.
I've been to Toronto a few times and do like the city -- it reminds me of a smaller NYC. But there wasn't a single meal I ate there that was memorable.
What about french whores? While watching Kids in the Hall I was lead to believe there were loads of french whores there.
They can all be found in the northeast end of downtown on St Catherine St.
The strip clubs there have this tradition of getting the groom from bachelor parties up on stage then stripping then down to the full monty, so if you aren't interested in showing your bird to a bunch of strangers and strippers on stage, then maybe don't go there for bachelor parties.
Jazz Fest is from June 27th to July 6th this year, that would be my choice of time to be there.