Well Montreal has more to offer but Quebec City might be what you're looking for.
Montreal's a big city (3.6 million people). It's cosmopolitan and multicultural. It's more bilingual. It's both modern and historic. The historic part of Montreal (the Old Port) is only one of many focal points for tourists but it is not the only part of Montreal. Montreal has excellent nightlife, shopping and a strong arts scene. It's all about eating and drinking and strolling around enjoying the sights, the parks, and the neighbourhoods. It's a city that can be explored on foot and also by subway. In the summer Montreal hosts dozens of festivals and the streets and patios are full people. It's an exciting, beautiful place - very cultured.
Quebec City's smaller (700,000 people) and it's much more compact. It's also much less multicultural than Montreal and its residents tend to be less bilingual but more French speaking than those in Montreal. It's also very historic and the only walled city north of Mexico so feels very old world. It's the site of an important battle (the Battle of the Plains of Abraham) which determined the future of Canada back in the 18th century. The city was founded in 1608 so you have a lot of historic architecture, and most of the tourist attractions can be reached on foot within the city walls. The historic part of the city is the focal point for tourists.
There are museums and attractions in both cities. Both cities cater to tourists with excellent hotels and restaurants. 2 days would suffice in Quebec City. In Montreal, 3 days would suffice. Of course, you could spend more or less in either city, depending on what you're looking for. For example, I wouldn't recommend Quebec City for people looking for a vibrant cosmopolitan city, nor would I recommend Montreal for people looking for a small village atmosphere.
I like both cities, but they both have very different personalities, even though they're the two major Canadian French-speaking cities.
p.s. Be sure not to confuse the French language for French-from-France culture. Provence, France cannot be found in Quebec any more than the English Cotswolds can be found in New England.
