If you overdress to the point where you're not wearing something you're comfortable in, it may make you fidget or seem uncomfortable. If you over-dress you run the risk of being too warm in an already stressful situation, and if you sit in the waiting room for any extended period you may end up with a sweat-y appearance or clammy handshake.
I'd suggest to take something you're comfortable in and dress it up a notch. Conversely, you could take a formal outfit and dress it down a little to make it more comfortable. The most important thing is to present a clean, comfortable, unified front. Matching belt to briefcase (if you have one) and shoes, few accessories like rings, clean shaven including your neck hairline, trimmed nails, etc. Pick a solid colour, keep the patterns to a minimum (the shorter you are, the more bold your patterns can be), avoid being totally neutral in brown/grays/blacks.