Normally the person that you love and like most in the worlds. The person that will be by your side no matter what, through bad or through worse. They put up with your worst moods just to be able to spend time with you through your best ones. You will disagree on some things but you allways work things out. They will normally be the funniest, weirdest, funnest, most amazing person on the planet. They will make you laugh when you don't even want to smile and if someone heard the convosations that you had with each other you would probably end up in a mental hospital!
My BFF is the best person on this planet!