It's hard to be too formal when interviewing for a job. You can always wow them with your individual taste after you're hired
My significant other is job hunting, and we disagree about interview attire. He is applying for software sales jobs, and he says that dressing more casually is appropriate for that type of job. I am nervous about it, because I think a suit and tie is standard for any white-collar position. What do you think?
It is hard to err on the side of too much formality when it comes to interview attire, unless you are interviewing for a hipster ad agency or for a job in the fashion industry. Like you, I believe that more conservative/formal is the better choice for a job interview. When you say that your guy shies away from a suit-and-tie combo, I immediately wonder what he's wearing instead. A jacket and tie is a fine alternative to a suit, but the watchword is professional—as opposed to sporty—which means that fabrics, colors, cuts, and patterns on ties and handkerchiefs are important.
If you can't convince your sweetheart of your (and my) point of view, ask him to ask a guy friend of his who's in a higher position than he is himself. You could be outvoted, but I bet your boyfriend's pal will agree that more buttoned-down is a better choice.
This brings us to the topic of displaying your funky side. Lots of people bristle at the idea that they should dress conservatively for any occasion, because doing so prevents them from showing their true colors, their verve, their style, their different-drummer aesthetic.
You can do all that once you get the job. Perhaps you've heard of the famous Beat author William S. Burroughs. They don't come any more radical than he was. Yet Burroughs always dressed in a gray flannel suit. He said, "I'd rather see them coming than let them see me coming." You don't need to trumpet your individuality via your clothes. There are plenty of chances to let an employer know what an original thinker you are through your actions in the job. When they love you, they won't care how you come dressed to work—within reason.