A best friend is some you go to for anything, someone who knows you the best, who can out a smile on your face no matter how you are feeling, or knows just the right thing to say to help you out. Not who you hang out with the most or who you gossip with.
A best friend is someone who is going to be straight up with you, tell you how it is.. Someone who can deal with you at your worst, and knows how to keep you at your high.