I am an international student. I came here in USA on August 2012. Since then I am working on campus. I have paid some tax. My friends in other university having same situation filed tax for 2012 using turbotax.com and taxact.com. They got around $1000 more than the amount they had paid tax in 2012 ( e.g.. They had paid around 500 as tax and are getting 1500 as return). They are giving suggestion for me to file tax using these site. I am willing to get OPT, H1-B fisa, and finally Green card in future. What is the best option for me to do? What will be the consequences or penalty if I file tax using these website?

Your friends filed INCORRECTLY!

By filing on-line, they filed as U.S. residents, filing Forms 1040 or 1040A and getting the American opportunity Credit, which offers a tax credit of $2,500, of which $1,000 is refundable, which means they get the $1,000 even if they had no income.

However, as non-resident alien, you (and presumably your friends) are NOT eligible to claim ANY type of Education Credit on your tax return, which would be Forms 1040NR or 1040NR-EZ, plus Form 8843.

You may want to tell your friends of these facts of life.