I didn't see anyone answer about the high rate of broadband penetration, so I'll explain.
Canada has the #2 rate of broadband internet availabilty/penetration in the entire world (South Korea being #1). Generally, no matter where you live, you'll have access to either cable or DSL. Shaw has a big ass fibre optic backbone running across Canada, so any place that has cable TV will most likely have cable internet. Rates are also MUCH lower than in the US, with a fully functional cable/dsl internet available for around $40CDN, even lower in some places.
Also, our drinking age is 18/19 up here depending on the province, marijuana is very close to being legalized, health care isn't 'free' if you can afford the VERY small premiums, but it IS free if you can't. Sort of... only pay if you can kinda system. Dental is not covered though, and optical is a province to province thing.
Movie ratings are different, with a movie that might garner an R rating in the US getting a 14A rating up here. Game releases are sometimes a few days later up here, but not always, and some games don't get released here at all, like the EA NCAA games (Although you can easily ship them from the US). Most big titles we get on launch day though.
You cannot get certain caffinated pops up here, such as Mountain Dew or dnL. This has to do with a law that only permits caffeine in dark beverages such as cola/root beer. Never fear though, because there is a Guarana powered series of Jolt flavours available, and all the same energy drinks you can get in the states. Also, our Coke uses cane sugar, which tastes MUCH better than the corn syrup used in American Coke, IMO.
Taxes on items range from 0% to 7% to 15%, depending on if it's food or not, and if your province has a provincial tax. Most food items are untaxed up here, unless it's like junk food.
I can't think of anything else at the moment