A new "Tax System"

I see many threads on ATS where someone is upset about one tax or another. So here is my question to ATS (from any country not just the USA). What do you consider to be a fair tax? What percentage would it be? Would it be based on “Sales”, “Income”, “purchases”? If we were to remove all income taxes, sales taxes, vice taxes etc. that we now pay, and redo the system from square one, what would you have it be based on, how would it be collected, and at what percentage?