Let the top one know, can't hurt. Don't lie to any of them to try to ranked higher because:
1) So many people do it, and the PD's know most of it is BS
2) If you get accepted, but they find out you lied about ranking them, it may bite you in the butt later (LOR's, etc).
3) It won't likely mean anything to them.
Similarly, don't listen to any that call you and tell you you are their #1 or "ranked very high" - many do it just to pad their own statistics and it just ends up screwing you. On of my classmates missed out on ENT because of that.
At most, you should send them a thank-you letter for the interview, expressing your sincere interest, if it is there, and maybe mentioning something that was (or wasn't) on your application that would make you stand out from the pack.
But send it via snail mail. A lot of PD's are still old foggies, and someone else reads their email or filters it for them. They'll respect the professionalism more. At least I would.