My best bud is my dog. (One time I compared someone to my dog as having similar characteristics. Said someone was inclined to feel insulted. However, a friend who knows me and my dog well jumped in to assure him it was a compliment of high order. And it was.)

As for human non-quadra buddies, my best friend is ESE, I have a relatively new dear EIE who I trust, and a SEE that I've always gotten along with (even if she overwhelms me sometimes). I sense a pattern.