1040EZ is the simplest tax form. It is only available for those who have no dependent(s). There are also other requirements, such as income related restrictions.
1040A $49.00
1040A is more complex than 1040EZ. Most taxpayers can use 1040A if they use standard deductions instead of itemized deductions, and your taxable income must be less than $100,000.
1040 Starting From $59.00
With 1040, you can claim all the deductions and credits in the world, and anyone can use it. You can itemize deductions, and you don't suffer the same limitations as with the 1040EZ/1040A.