The following list was based on my knowledge of Montreal, my home town, and a lot of feedback and discussions on the Montreal TA Forums. I hope this can help future travelers in planning their trips.
A few things to know:
-Museums are mostly CLOSED ON MONDAYS.
-You don't have to do everything! Base this list on your own tastes, where you're from and who you are traveling with.
If anybody has comments on this list, i am open to feedback and any opportunity to improve these things to do.
Metro station is Place-d'Armes.
Old Montreal district and Old Port are located together. The cobblestone streets, the old New-world buildings, the street performers all make this the top attraction for Montreal. Tourists are abundant and so you will find restaurant and souvenir shops with inflated prices. Restaurants are usually so-so but there are a few gems here. The beauty is in the setting. Horse carriage rides are highly recommended, but i dislike any other kind of tour. Old Montreal houses some great activities such as Pointe-a-Caliere Museum, Science Museum (great for kids), Labyrith du Hangard 16 (for young kids), and rental bikes etc...
Montreal's most beautiful church, located in Old Montreal. 5$ charge to visit the church, which goes towards restoration costs. A light show happens every evening at the cost of 10$
Mount-Royal park is in the middle of Montreal. It's a beautiful place to have a picnic. The main attraction is to go at the top and lookout onto the city. Particularly stunning at night. There are several ways to access the park, the best being bus #11. All alternatives are listed on the Mount Royal park website's FAQ.
My personal favorite museum. Very good for kids but also great for adults. Each room is enclosed and mimics a climate from a part of the world, includes tropical plants and even animals. Note: As of December 2010, the Biodôme is now reopened.
A year-long farmer's market. It's outdoors but a solid roof protects you from rain and snow. Better in the summer of course, when local produce is abundant.
One of Montreal's most prized museums. Located in Old Montreal, this museum has several exhibits, permanent and temporary about archeology and history.
Refer to their website for temporary exhibits and events. The permanent exhibit, which is quite large itself, is completely free.
Good for kids. A museum dedicated to insects. Once a year, they have a event where insects are served in various meals... Good for the extremely adventurous.
Located in Old Port. Particularly good with kids, young or older. This museum is very pratical oriented, with many experiments. Some towards science other towards technology and how it is used in the fields. The hands-on and simulation approach makes this fun for children and adults alike. Also, annexed to it is the IMAX theatre. TIP: Present your CAA or AAA card for a good discount.
Small compared to most cities. The main reason i'm including this in the list is that it is a good place to get food near Old Montreal. I recommend Maison Kam Fun or Ruby rouge for dim sum, or Little Sheep for mongolian Hot Pot.
The egg tarts at Harmonie bakery are a must (other pastries are great too).