I'm an H1B visa holder and I have been filing form 1040NR-EZ for the past 9 years. First as a student and now as a worker. I just came across the Substantial Presence Test and realized I can be considered a resident for tax purposes if I pass this SPTest.
So, my question is, should I just file form 1040EZ without any other form? What about deductions? Do I use the regular State income tax as a deduction or can I use what residents usually use, $5000?

Any help would be appreciated... I'm just trying to get a little bit more $ back.

Thanks.

You filed incorrectly since your F-1 exemption expired at the end of the fifth calendar year.

File Form 1040EZ for 2008, then amend every year in which you were considered to be a resident alien.

For 2005 and earlier, you have forfeited any refund due, but if you owe taxes, those must be paid plus interest. You can ask the IRS to waive any penalties involved if you owe additional tax.

On F1 you are nonresident for 5 years and after that you must file resident tax return. On H1-B, you days are not exempt from residency. If you are married, you can file joint return as residents. Read about F1/H1-B tax filing: Your U.S. Tax Return: The U.S. Visas

You should file amended tax returns for 2006 and 2007 as you can still get the refund.