This letter lets a family member know that he or she is also your best friend.
1234, Main Street
Boston, MA 02123
07 April, 2005
<Recipient Address Goes Here>
It seems like I know so many families that do nothing but fight and make each other miserable. It really makes me appreciate how special our relationship is. Not only are you my <relationship>, but you're also my best friend. I wanted you to know how terrific I think that is and how much I cherish every moment we get to spend together. Not only are you fun to be with, but you're a fantastic listener, a kind heart and a staunch supporter in time of need. You've always been there for me, no matter how outrageous the situation or dire the need. That kind of friend doesn't come along every day.
Some people spend their entire lives looking for a friend as wonderful friend as you, and here I was lucky enough to be born right into your family! I just want you to know that our friendship means the world to me and there's nothing I wouldn't do for you.
encl: <List of enclosed items goes here>