I am of the mindset that we should have a flat tax for EVERYONE! To me, that's the only version of "fair share" that is acceptable and here's why:
My boss makes roughly $245,000 a year running his own private consulting business. His wife wanted to get a part time job for extra income, however if she made more than $5k in a year, they'd be bumped up to the $250,000 tax bracket and pay $10,000 more in taxes which means they actually LOSE $5,000! This gives his wife NO incentive to work! Why should ANY family be punished for working harder and making money?!?!
Here's how I see it: I have always thought a 10% flat income tax would be reasonable (although I wouldn't mind Herman Cain's 9% since it'd be cheaper

). Here's how you do your taxes: add up all income and move the decimal point one place to the left! DONE! Bye bye IRS (except for a few auditors). All of you who say "the rich should pay more!" are right, AND THEY DO! THEY HAVE FOR YEARS! If you make $5,000 a year, you pay $500. If you make $5,000,000 a year, you pay $500,000! Now some people say this is "regressive" because people who are "rich" can afford MORE than 10% and people who are "poor" CANT afford 10%, but I say that if you're "poor" you're probably getting other money from the government anyways so you'll probably recoup your $500 (not that I really agree with that, but oh well, one step at a time).
For as long as you have tax "brackets" there will always be some point where an individual will get a "raise" that will actually HURT them, instead of helping them and that is WRONG!
And a sidenote for some food for thought, a recent study was done that said, even if you raised taxes on anyone making over $250,000 to 75%, you could still not raise enough in tax revenue to offset the debt limit increase! (That means we need to cut spending!)