I definitely like tighty whites--classic fly front--for physicals. The white socks are an interesting touch. I think bare feet increases the patient's embarrassment in that having only briefs on for the commencement of the exam emphasizes the fact that only the embarrassing body parts remain covered. The white socks do increase the nerd factor, however. If I were going to add the white socks, I would definitely want the tube variety rather than more athletic-looking quarter length ones.
It seems from the responses to this post that a lot of people also prefer tighty whites for physicals. I am curious what brand(s) people like. I favor Calvins or Jockeys because the fabric is a little thin, the fit tends to be skimpy without having a sexy look, and I like the waist bands.