What is the best option and why?

The current system is unbalanced, so how would it better be implicated?
It seems like no tax at all would be unrealistic, so if not the current income tax, which would you prefer and why?

-Flat Tax- everyone pays the same percentage of their income.
-Federal sales tax (what is sometimes called the Fair Tax)
-Other?

I am really on the fence about this one as all the options have good pluses and minuses.