mrbill said:best system would be a national sales tax, not a flat tax. All a flat tax does is flatten the tax rates, it doesn't fundamentally change the system, just the rate structure. The IRS would still exist, as would audits, complexity of the tax code, tax evasion, etc. A sales tax system would eliminate all of this. However with all this said I hope the tax system gets even more confusing than it is as I am a CPA (well soon to be) and may very well be working in taxation for awhile...if I don't land an investment banking position.
This would crush poor people. However, the income tax does perpetuate the absurdity of taxing money before it is spent.
None of those thigns mentioned above need exist, if you just make a flat tax truly flat (about 15%) and strip away all the deductions.
People under a certain income would be exempt, and everyone else pays the same rate, whether income, capital gains, etc.