Ok, this has probably already been done, but it never hurts to revisit topics every once in a while In all five series, which is the best friendship (of those listed that is)?
As much as I detest O'Brien I voted for the Bashir/O'Brien friendship because I do think it turned out the best, especially considering the rough start between the two men.
This will sound like a cliche', but you can't beat the Big Three: Kirk, Spock, and McCoy. Those three would do anything for each other. They had their disagreements, but in the end, they were completely loyal. Even though Spock and McCoy had their "feud", when push came to shove, they were there for each other.
A billion fanfic authors can't be wrong - it's Kirk and Spock. (although the idea of them as lovers is one I could really do without)
All we ever saw Kirk and Spock doing was playing chess. O'Brien and Bashir drank, fought the Alamo, played darts, discussed women..
But Kirk and Spock were working with a huge culture gap and were friends. Bashir and O'Brien were from very similar cultures.
The Triad of Kirk, Spock and Bones, followed by Bashir and O'Brien. Honourable mention to Tom Paris and Harry Kim,
Oh believe me I'm all for Kirk and Spock and their deep bond. I think it's a soulmate kind of thing that transcends regular friendships. But what we saw on screen of Bashir and O'Brien was the stuff of human friendships that most people desire. Buddies, comrades, confidants, playmates.. and good point that there would be less of those activities because of cultural differences with Kirk and Spock.
Bashir/O'Brien. Two complete opposites who find common ground in their situation. And they way it was written/acted, it seemed like a real friendship.
Kirk and Spock. Star Treks II, III, IV, and even V really drove their friendship home. Heck, it even resonated in XI as something that crossed over into other realities.
I voted O'Brien/Bashir for the the reasons Teacake listed. They may have been from similar cultures...but they were very different men. I really enjoyed their journey (and the fact that they were shown to have fun together, to actually play) It just seemed to be a very real friendship to me.