Josh, it’s always a good rule of thumb when going for an interview that you look as presentable as you care to have your prospective employer see you. It’s better to over-dress than under-dress, so I’d leave the jeans with holes in them and your Nirvana t-shirt at home.
We won’t say that you need to wear a suit, necessarily, but I’ll put it this way: there will be hundreds of people there looking for a job, and only a few dozen people will be hired. Like it or not, that first impression you make is going to be the long walk from the seating area to your interviewer’s table, so make sure that first impression is a good one!
-The Mailbag Guy