I've only worn a suit once for a job interview, for one of my first, because the company sounded like they cared about that (I even called them to verify!), and the company sounded interesting enough to make the sacrifice. But at the interview I was terribly overdressed, and sat opposite two typical techies in scruffy shirts and dingy sweaters.

I really don't see the point of suit and tie. Wear a nice button-down shirt. Then you're always good.