Forbes magazine came out wit their Tax Misery & Reform Index, which tracks overall tax burdens of various countries around the world. Take a look at the comparision between Canada and the U.S on income & payroll taxes for a family of four making 50,000 Euro (at today's rates, that would be roughly $64,000 U.S. or $70,000 Canadian) - the net take home for canada is roughly 72% while in the U.S. it is 80% on average. This doesn't even factor in the differences in sales taxes and other forms of taxation.
If you want to point out why the U.S. standard of living is better than that of Canada and all of Western Europe - compare the tax rates for starters.
H.T. Tax Prof Blog