I bought a very helpful book from the Princeton Review entitled "Med School essays that Made a Difference", or some such thing. It had profiles of about 30 applicants with their stats, a/s/l, and their PS. Some of them were about incredible things, like helping in third world countries, having research experience, blah blah. Despite the unique experiences, some of them I simply couldn't get through. I was too bored.
I don't think the essay should be a way of working in your accomplishments, or really trying to "sell yourself" to the admissions committee. I think it should answer the question "Why do you want to be a doctor, and why should we consider you at this school"? You can do these things in a way that demands attention, rather than makes the reader lose interest. Put your heart into it, without being overly candid or sappy. There's a way it can be done, and you just need to find your way of doing it.
Here's another tip: get three people to read it for you. One should be a close friend, who knows you well and can see if your good qualities come through. Another should be someone who writes well, and can help you with editing. And the third should be your pre-med advisor, who can tell you if it will satisfy many admission committees. If you're a non-trad (like myself), you may need to make some new contact with old friends to do this. It's just a thought anyway.
Oh, and that book of essays nearly put me over the edge. It has profiles of students with perfect GPA's, perfect MCAT's, and they STILL didn't get into schools they probably considered safeties. It just goes to show that the numbers aren't everything!
Good luck.
