This is credits to Dalinah, taken straight from her blog, which i feel is extremely true.

"What defines a best friend? What are the requirements to be a good bestfriend? How many hours a week does it entail? Stupid questions that have noanswers. A best friend is not defined by how many times they talk on the phone,or how many hours they hang out together. It is not defined by how manysleepovers they gossip at, or how many inside jokes they have. There are norequirements or laws that state that a good best friend must hang out with themevery weekend, or tell each other every little detail. A best friend is a matterof opinion. It is the person who has been there for you through everything, notjust through the fun things, or the little things. It is the person that youcall when you are at your absolute worst, it is the person who saves you whenyou didn’t even notice that you needed saving, mostly it is the person who accepts you for who you are, and the person that you are becoming"

-Unknown.