Despite being so completely awesome, I did get my fair share of rejection letters when I was applying to medical school. However, there were a few times when the tables were turned, and I had to tell a medical school that wanted me that I wasn't interested in them. I crafted the following letter to send them:
Dear Medical School:
With sincere regret, I am writing to share what I believe will be disappointing news. I have considered with care your school for admission. Unfortunately, because of the rigorous competitiveness of the medical schools that have accepted me this year, I am unable to attend your school.
I very much appreciate the time and effort you have spent crafting and compiling your brochure and application materials, and the interest you have shown in me. The fact that I am only one person dictates that I must limit my enrollment to a frustratingly small proportion of those seeking my enrollment. I can assure you that your school was considered with thoroughness and care despite this disappointing outcome. I commend you for your patience during this interview season, and I am aware that my words may do little to assuage your disappointment.
In closing, I wish to express my regret that all medical schools can't be allowed to fulfill their aspiration of educating me at their fine institutions. Because of your excellent medical facilities, it is my hope that you will find the students you seek for your class of 20xx and beyond, be it as a medical school, or else maybe as a dental school or clown college or something.
Feel free to use it if you need to.