Pros: Great shopping, restaurants and varied things to do
Cons: Poor roads makes driving around not much fun
A bit of geography will help you picture Montreal and get you orientated. Montreal is a lemon shaped island, if you can imagine the lemon with its pointy ends pointing east - west. on the south side it is bounded by the St Lawrence River, and to the north by a smaller offshoot of the river that forms a loop. In fact, there are two islands formed by loops, the northerly one is Laval, the second biggest city in Quebec (by population) but more like a huge suburban development and nothing worth seeing, no offence Laval! But Montreal island has a good deal to offer the tourist.
Flying to Montreal, you arrive at Pierre Trudeau Airport, until recently called Dorval. The first thing you see on leaving the airport are some not too picturesque suburbs and industrial areas, but keep you're eyes up to see the city's skyline which is much more pleasing. You'll probably notice too that the roads are full of holes and cracks which can make driving around the metropolis tedious, a regrettable feature of the city.
One big attraction, especially for Americans who cross the border, which is only 30km away, is the shopping. Perhaps the most well know street is St-Catherine. It's here that you can find and get lost in the underground shopping malls; kilometres of linked malls with more clothes and shoe shops than you can imagine. Up on street level you can find Ogilvey's, Montreal's version of Harrods; OK not quite as chic but up market and not too pretentious with a good place for lunch in the basement, serving very good salads, paninis and quiches. Further along St-Catherine are many clothes shops, Simons being popular, as well as fast food restaurants and an attempt at a red-light district which is strange on a popular shopping street.
A main attraction is the Old Port. This is the original heart of the city and retains many old buildings and the only other Nelson's Column that I know of outside Trafalgar Square. Small streets are home to many gift shops, restaurants and cafes making a pleasant atmosphere and an interesting place to wander around. There are a number or art galleries selling paintings and etchings of high quality and many reasonably priced limited prints can be bought showing scenes of Quebec as well as other subjects. Towards the quay side is a long park area that is popular in the summer and has an IMAX theatre as well as some other attractions. It also gives the chance to get close to see boats and ships, many big cruise liners arriving at the port on route to or from New York, and often in autumn as part of a trip to see the colours of the fall leaves.
Between the Old Port and St-Catherine is the financial district (all within walking distance). It has some fine buildings and a few big hotels such as the Queen Elizabeth, perhaps best know for Yoko Ono and John Lennon's 'bed-in' in protest against the Vietnam war. Victoria Square, on Rue McGill has had a recent makeover and has an entrance to the Metro that came from Paris, one of the renown Art Nouveau designs. It should be mentioned here perhaps that the metro is a good way to get around the city, however the most interesting parts are in the centre and easily reached by walking.
Museums are not so numerous but the Museum of Fine Art (Musee de Beaux Arts) is a very good one. It has a permanent exhibition which is free to visit and some excellent changing shows. It is worth checking the schedule before you arrive to see what will be on display. Almost unique is the Canadian Centre for Architecture, a museum, repository and centre for information on buildings and things to do with the designed environment. It has original and highly recommended exhibitions which change periodically and if you're at all interested in things urban and architectural history it is well worth a visit. For nature and garden lovers there is also the Botanic Garden, located in the east of the city. It's easiest to get there by the Metro if you're not in a car, the nearest station being Pie IX. It has a magnificent Chinese garden, built by Chinese workers and paid for by the Chinese government. The Japanese garden is also very good and as well as this there is a large collection of Lilacs and an impressive rock garden that rivals any anywhere in the world. While you're there you won't be able to miss the Olympic stadium even if you want to. It dominates the skyline for miles around and can be visited and the tower climbed to see an expansive view. In the same complex is the biodome, a collection of different ecosystems, a kind of indoors zoo much loved by children.
For people that like night life and clubs then there are lots. The area around Rue Metcalfe, just off St Catherine has plenty, with many restaurants including New Town, owned by racing driver Jacques Villeneuve. Boulevard St Laurent has many restaurants and clubs catering for those that like the more refined style down to the dark and dirty. Many of the smaller roads off of St Laurent have unusual shops and small restaurants, a real eclectic mix.
So that's a taste of Montreal. If you're going to that part of the world then it's worth a visit and makes a good base for skiing trips in the Laurentian Mountains (2 hours drive to the north) or even a visit across the border to New York, 6 hours drive away (or a bit more by bus which go regularly from Montreal).