I was full-time student in 2010 with F-1 visa till may-10, then I was on OPT from may onwards and working full-time on my opt since then, what form should I file in 1040 or 1040NR for my 2010 tax returns. Also, am I eligible for 1098-T tax benefits?

You will file nonresident tax return and Form 8843. You do not get any 1098-T deduction or benefit. Your U.S. Tax Return: U.S. Tax Filing Requirements for Non-Residents (http://taxipay.blogspot.com/2008/03/us-tax-filing-requirements-for-non.html)