The biggest tax is when the government increases the currency in circulation (money supply) to 'stimulate' the economy. This creates inflation and inflation is a tax. Those at the top of the economy have their pay indexed to fight inflation. Those at the bottom don't have that privelage and their spending power diminshes - i.e. they lose real wealth. The Bank of Canada govenor - appointed by the Prime Ministher - is the most aggressive and dishonest tax man in the country.
The second biggest tax is deficit spending, which is a tax to be paid later.