Hi
I (L1-visa) had been here in US for more than 1 year and my wife joined me in dec-5 ,2007.Currently she is not having any job and is in L-2 visa.
How can I apply for a tax jointly when I think I can go through the form 1040-EZ ( since I have been here for more than 180 days) ,but she is here only for 25 days for year 2007 and I think she needs to go through from (1040NR).

What is the best way to approach this situation so that I can get maximum returns.

You can file jointly with your wife and you both CHOSE to be treated as resident aliens. This will allow you to claim the $10,700 joint standard deduction plus two $3,400 personal exemption (for yourself and your wife).

The downside is that you must you must declare ALL 2007 world-wide income. There are two offsets available, by either claiming a Foreign Tax Credit (Form 1116) or a Foreign Income Exclusion (Form 2555).

Even with the downside, this is probably the best way for you to file

You have already spent more than a year on L1. It means that in 2007 you must file resident tax return. Since you are married, you can only file as Married Filing Separately (MFS) or Married Filing Jointly (MFJ). And as Atlanta Tax Expert said, MFJ is probably the best option for your.