From
another thread two weeks ago:
You could try to say something like "you are one of my top 3 choices" or even worse "I will be ranking you very highly", but that won't really make a difference. No program director would hear that statement and think "ooh, maybe this means we'll be her #1 choice". Like I said, you only have 2 plays. "You're my #1" -- or not. The program director knows that you will profess your undying love to your #1 choice, whichever program your #1 choice may be. The program director knows this because applicants exhibit this behavior: universally, applicants will tell their #1 choice "you are my #1 choice" because they think it will induce the program to rank them more highly. (Of course, applicants only do this because everyone else is doing this. Clearly all applicants would be better off if no one professed their love to their respective #1 choices, but this is an unstable equilibrium because any applicant has an incentive to break rank.) The program director also knows that you know that you can (ethically) only profess your undying love to a single program. So when it comes time for you to say something to the program director, she knows that if you do not tell her "you're my #1", then she is not your #1 choice.
So really what you should do is just keep silent. Who cares if the program director says "let's keep in touch", who cares if the program director leaves you a voice mail the day before rank lists are due, etc etc. Sure, this takes cojones -- but you should do this because it is the right thing to do, and if everyone behaved similarly then the Match world would be a better place. (This is not just cheap talk. I did this myself, and things turned out just fine.)