Please ignore the rudeness that you experienced in one of the previous answer. Postal codes in Canada define a much smaller geographic area than do US ZIP codes, so it is fairly easy to zero in on your situation with just a Postal Code.
The Montreal area is rich with both local signals and those from Mt. Mansfield in Vermont. Most people in your area are used to seeing the Vermont stations in addition to local Montreal stations, however, in your location, the Mt. Royal signals and the Mt. Mansfield signals come from two different directions, and vary widely in signal strength. Additionally, Montreal has several digital signals of it's own, but most will not convert to digital until August 31, 2011, however, the Mt. Mansfield, Vermont stations are currently ALL digital.
Since the Mt. Royal stations are very close to you and very powerful, we cannot really use a preamplifier without causing some overloading conditions, so a larger antenna that would be normal is called for, especially if you want to see the Mt. Mansfield stations. Also, since some Montreal (channels 2 and 6) are low-band VHF, we need to choose a good all-channel antenna to insure good reception on all of the available stations.
In this case, consider using a Winegard HA-7082P VHF-UHF antenna mounted on your roof, and use a rotator like a Channel Master 9521a or an AntennaCraft TDP-2 to turn the antenna between Mt. Royal in Montreal and Mt. Mansfield in VT With this combination, you will see everything from Montreal AND Vermont without any trouble, and the antenna system should remain reliable for many years.
Here are links to the equipment:
http://www.winegard.com/kbase/upload/HD7082P.pdf
http://www.channelmaster.com/product.php?catID=34
http://www.antennacraft.net/Rotator.html