I've never said no to a candidate who overdressed for the interview. You don't necessarily need to wear a full suit. Use your best judgment. Know what's expected of you in your line of work. When in doubt, wear something more formal rather than less formal.
A trick I always use in interviews is to carry a notebook. I rarely wrote in the notebook, but bringing it with me to the interview still conveyed a sense of professionalism and organization that impressed many hiring managers.