It kind of depends on what you are referring to. A 580 can usually get you a loan approved for FHA financing. A 620+ is very good and can get you approved with most lenders. However, for higher loan financing or if you need to obtain mortgage insurance, a score of 700+ is typically required.
If you would like to know your credit score, I can get you a credit report in about 15 seconds - no obligatin to obtain financing.
Bank of America Home Loans