There are few things more nerve racking than an interview. Especially when you don't have a job, trust me, I am going through it now.
You want to come off as confident, personable, smart and hardworking; all without being overbearing. You want to ask probing questions, understand the job on offer, the expectations, the employer and the opportunity as it pertains to longer term career prospects; without making it sound like this job is merely a launching pad. A job interview is a balancing act and you are the one walking the tightrope.
The last thing you need to worry about is what you put on. An interview isn't the place to push boundaries, well not yet in the corporate world. There are some places, like advertising, fashion and media which can certainly be a different story. For the rest of us though a suit is always a safe bet for the big day. I always had a hard time finding suits that fit me, I am relatively small with almost no hips so the standard faire on offer at the local department store never worked for me. Here are some suits that are cut slimmer and are a bit more modern. Perfect for that first corporate job or for the dream job 10+ years in....
Good luck on that interview!