I don't like the idea of income tax at all, period. The fairest system would be a "value added tax" on everything that is bought except food and medicines. I like this much better because the richer you are, the more things you buy and so the more the richer would pay in taxes. You wouldn't see a poor person buying a car every year, but the rich do.
This would be a much better tax also because if politicians raise those taxes too high, the economy will balk and fight back. If the tax is too high, people will stop buying. If it's a fair rate, and there's no income tax, people will spend more money bolstering the economy.