Understanding. Honesty. Views and/or things we have in common. I think it's very important to know what you are looking for in a friendship, just as much or maybe even more, than you want to know what you're looking for in a relationship. At the end of the day a friendship is also a relationship, the two of you get so close and you have to chip away at each others' flaws to find the really honest friendship on the inside.
What do you look for?