What is the best way to file 2009 taxes for my non resident wife. She currently live in argentina and I am living in the states for work? Does she need a ITIN?

More than likely, filing jointly is the best option for you, but, to know for sure, I would need to know what YOU make and what she makes in Argentina.

She WILL need an ITIN if you file jointly. That is applied for with Form W-7 WITH the annual tax return.