If you find yourself in Montreal, make sure you go to the top of Mt. Royale and look out over the city for a pretty amazing view. After that, It is definitely worth checking out McGill University which happens to be constructed on the side of a giant hill (and if you can, try to get into one of the parties later on. It will be incredibly weird, but definitely memorable). Also try some of the micro breweries (Dieu du Ciel in particular). Just do it. You'll thank me. Finally, don't be like me, a fool who stayed in one place. It is the second biggest country in the world. Go out and adventure through it!

Overall Impressions

The stereotype is true. Canadians are very friendly
Everyone in Montreal speaks perfect French and English
Crossing into Canada is far easier then crossing back into the US
McGill had amazing architecture
Nightlife is great and full of music
Dieu du Ciel is the best brewery ever (outside of Vermont)
Lifestyle is more relaxed than the US