Killer I concede the current necessity for a federal income tax as a necessary evil but I would get rid of all credits, deductions, loopholes etc and have a simple progressive system based on gross earnings in the year.

1. No income tax paid
2. 0.5%
3. 1%
4. 2.5%
5. 5%
6. 10%
7. 15%
8. 20%
9. 25%

That being said my fantasy federal gov't would not require a federal income tax to fund it.