It's natural to want to impress the interviewer, but there is such a thing as going overboard. I recently introduced a friend to people to network with since she was job hunting, when I realized she had a "networking face." She was definitely more polished, but the way she carried herself seemed a little less genuine than her regular self. I'm a firm believer of staying professional yet keeping it real, and I think you can definitely find a good balance. I took my friend aside and told her that her regular self was a lot more likable than her job search persona.
I think if you're more genuine with someone, you'll get a more sincere reaction out of them. People will notice if you're not your real self and they'll treat you the same way as well. To stay memorable, it's ideal to have your interviewer feel comfortable and actually remember the real connection she had with you. So when interviewing, keep this in mind: stay professional, but be yourself.