I believe people from these countries are so similar that you wouldn't even feel you're in a different country when you visit either. They are both Democratic (at least when it comes to internal affairs)
I go with the US because of several reasons:
1) Jobs are definitely more in The US than Canada
2) Taxes are much less in the US than in Canada
3) US has much much wider range of climates, from very cold states such
as Alaska and Main to very warm states, such as Mississippi and Florida
to very Mild states such as California to very rainy states such as
Washington. Canada has definitely nice areas with good weather,
however it does not match the climate diversity of the US. and
generally Cold
4) Canada can be very very expensive! Buying a house in Vancouver
(which is a nice city BTW) can cost you as much as buying a house in
San Diego, California, which, needless to say, has a great climate with
mild temperatures close to the Beach to swim, 2 hours drive to ski, 2
hours drive to Desert! and it's a pretty safe city.
5) US is more Business Friendly
Canada does have some positive attributes, such as Health care. Canadians are very educated and know whole a lot about outside of their countries than we Americans! in fact that is true Even when it comes to the third world countries!

The immigration laws in Canada are much more inviting than the once in the US, most likely because of the resources that are available in Canada vs qualified workers that are available. you can migrate to Canada by investing , being a qualified worker, or for family reunion. you need to provide 150k in order to get an immigration visa vs 500k in the US. However, you will not receive the 150k back when applying for Canada!! in the US you will receive the 500k after 5 years. applying as a qualified worker for Canada is much easier than the US. it is virtually impossible! since there are so many qualified workers in the US. You need am invitation from the company that is willing to hire you Only! then they will provide you with a visa that is good for a few months and has to be renewed.
anyways I love both countries
