I love Van Horne Pizzeria; every single time I've gone there or ordered from them, it has been nothing less that an awesome experience.
The actual shop isn't anything fancy, but their pizza is fantastic. The workers there are always extremely friendly and helpful, as well as being both French and English speaking. Delivery is free, service is great. The pizza isn't the best I've had, but it is the best I've had in Montreal for the price! The only downside would be they're not open super late, so make sure to order before 10 or so.