I can't tell you how many times I've answered this question. Don't even know where to start anymore...

For me, having an established best friend is important because, well, everyone needs a go-to person. No matter who and what personality type you are, you'll get the need to talk to someone about it, be it human or animal. Keeping problems to yourself only works for so long, and having a designated person to consult is beneficial in many ways--one being that this person'll have an archive of your past problems and will have an easier time relating them to the current problem to calm you down and potentially fix said problem [/vagueness]

A best friend, for me at least, means that this person is someone I can always go to and in a way kinda...like...completes me? It's hard to describe in words, but there's a feeling you get around that person that just feels right. You're protected and can say anything without fear of being made fun of (( aside from some teasing ;P)). It's nice. I hope everyone gets a chance to feel the way I do at least once before he/she dies. No matter what scuffle I get into with family or friends, I know I have at least one person I can fall back on and trust to tell me exactly what she thinks.

There'll be a multitude of annoying-ass people out there who'll say pretty words and be all touchy-feely, but few people'll actually put in enough effort to be FUCKING REAL with you. Those few will make good best friends. [/potential rant]

...Did I answer the question yet? D;