Naomi and all the girls.

Naomi and annie.
I used to love silver and annie, but I don't see that closeness anymore.

of course they are like sisters to eachother
Adrianna and Silver used to be close 2 before Silver broke their pact
Adrianna and Naomi were best friends in season 1 but they sorta drifet apart
Naomi and Silver were best friends for a while before the show started but then Naomi told the hole school about Silver's parents wich stopped their friendship but they became best friends again in season 2 and 3 but after that they just somehow aren't that close anymore
Adrianna and Annie well they are friends but they just never really been that close at least not until Adrianna started dating Dixon wich brought them closer to eachother but still not that close
and of course Annie and Silver, after Annie and Naomi i would say that these 2 are the closets
but it is Naomi and Annie who are the closets and i love how their friendship has developed over the years
so they have a great friendship.