I was on F1 student Visa until October 2006 after which shifted to H1-B visa. I have been in Florida for the past 6 years and I've currently moved to Arizona on H1-B. What Tax return do I need to apply? Since I have been in Florida for 6 years and moved onto H1-B only by October, Should I file a student return , resident return or a H1-B tax return? - please let me know

If you have been in the U.S. for six years, you must file as a resident alien (Form 1040EZ most likely).

You lost your F-1 status for tax purposes at the end of the fifth year!