I arrived in US in Sep, 08 and salaried since then in US with monthly IRS deductions deducted at source. I have one dependent child of 1 Year Age. I am married - Spouse is Homemaker, has SSN. My family arrived with me in US in Sep,2008, they are living with me since then i.e. today 4/4/09.
My Total Income for 2008 < $23K.
My W4 for 2008 states Taxable status as Non Resident Single.
I have received W2 from my employer for 2008.
Ideally I like to file Joint Return and Claim for my dependent.
I went to two or three tax consultant, some say I should apply 1040, some 1040NR. Which form should I apply for? What Can I do to save taxes - my Tax Deducted at Source was ~ 4500K for 2008?

I am on L1

You can file resident tax return as Married Filing Jointly.

You will have to wait for 5 months to file your tax return till you meet the Substantial Presence Test in 2009.
You will get standard deduction of $10,900 and exemptions for both of you and the kids.

You must both declare your worldwide income for 2008. If you have any foreign income, and on that income you paid taxes in the foreign country, then you can claim foreign tax credit (Form 1116) or you can use Foreign Earned Income Exclusion (Form 2555).

You will complete forms W7 (application for ITIN) for your spouse and children and attach with your tax return.
Read about L1 tax filing: Your U.S. Tax Return: The U.S. Visas