How about the same percent tax on every income dollar of every person in the US. No exceptions at all. No exclusions at all. No exemptions at all. Equality of taxes for every individual before the law.
That would work almost as well, but you still have to file and the government is still involved in knowing how much you made and where the money came from, and can raise the rates anytime they want. A fair tax means you only pay a tax when you spend your money so it hits everyone absolutely the same. The only way a fair tax would work, however, is if there is a constitution amendment outlawing the income tax, otherwise it would only be a few years before we would have a sales tax and an income tax.