This was a tough one. Funny enough, I've recently heard relationships between men and women described best as this: Friendship between women is like a garden that constantly needs tending. If you don't tend it enough though, it ends up withering up and you have to start all over. But when tended properly, the blooms are absolutely gorgeous and wonderful. Friendship between men is like a giant tree. You can ignore it forever, but it grows on its own and it's always there and doesn't resent you for not tending it.
I've had issues with deeming someone that 'tip-top' placement as a best friend these days. Having a best friend should be something natural, it should be someone you admire, look to, and have a great time with no matter the situation. Someone you trust, and someone you will always be there for.
The last person I called my best friend was my room mate from college, Alicia. She dropped out when she realized there were greater and bigger things calling to her in the world, and it wasn't artwork. I can only hope the best for her, and while we have lost touch over the years (my losing her phone number and her not using any social networks doesn't help), I want to treat this friendship like a tree. It doesn't need much tending, it keeps growing, and it's always there, no matter how much time has passed. Here's to you, Alicia, where ever you are, and whatever you are doing.