I prefer my doctor to dress professionally. The last time I saw my GP, who usually dresses well, she had on a revealing top with her girls almost hanging out. I was really shocked, as it was not like her, and I was a bit put off by it. Perhaps she was showing off her new tan, as she'd gone south for March Break (she's from a hot climate and hates the Canadian winter!), but I just found it not professional.
Male doctors, I like to see in shirt, tie and lab coat but that is rare these days. As long as they are neat, clean and presentable ie. no jeans, torn clothing etc., I can live with that.
The turn off that sticks in my mind most about a doctor was when I went to a walk in clinic in a large city, and the doctor came in cracking gum! I don't remember what she was wearing, but she had quite a bit of makeup on, and was chewing gum, cracking it with that loud, annoying sound. That really, really, really put me off and I never went back there.
As for attractiveness, it's not important to me, male or female.
In play, shirt, tie and lab coat of course. Scrubs are good, too, for an occasional change of pace.