You know what really grinds my gears?!

[Ken]

I've shown up at very casual places in a full blown interview suit and stuck out like sore thumb/been teased for it.

That being said, I still always air on the side of being over-dressed for an interview. If I know for a fact that every employee comes to work in torn cargo shorts and flip-flops at a particular place, I'd probably scale it back to a button up and/or sweater and khakis/slacks. If I don't know, or if the places requires business-casual or higher of its employees, then I'm definitely suiting up.

Exactly, at worst you are given some gentle teasing. I would always rather err on the side of being over prepared/over dressed. Unless you are specifically told not to wear one I would always do so. There's no real negative.