I'm sure there are enough pages on the internet devoted to picking the perfect interview attire for a professional job that you could spend your entire lifetime reading it. I think it has more to do with your personality than anything else.
Me, I've never worn a full suit for an interview. A nice dress shirt, tie, expensive pair of slacks and my pair of wing tips have gotten me everywhere I've wanted to get to. Fully dressed up is not really my style and I think dressing ever so slightly gives a good message.Then again I'm an adult male who never cut his hair so I think that probably says more about me in an interview than any outfit ever will.
I'll say this: you're never going to get marked down for being overdressed to an interview, but this industry and this profession in particular tends to err on the business casual to truly casual side of things - though we haven't quite managed to reach maintenance status in the casual dress department yet so it's a work in progress.