It is so, so much easier to find well-written AOS fic than it is to find well-written TOS fic. But this is a problem! AOS!Kirk/Spock is TOS!Kirk/Spock minus epic friendship plus Uhura. And ... well, the more TOS I see, the more bewildered I am the film went the Spock/Uhura route (not least because I apparently have a side gig watching the old films and shipping Scotty/Uhura like burning) but, this said, I really don't want to sacrifice Uhura to the Gods of Slash, because she's too awesome for that. The entirely excellent compromise is Kirk/Spock/Uhura, which is fine, but at that point they have rejected the ghosts of TOS, and that is not the dynamic I'm craving.
Hilariously enough, when I'm reading AOS fic, everyone is definitely AOS Kirk and Spock and Uhura and Scotty et al, and same with TOS fic -- but Bones is always just Bones. I can flicker back and forth between their faces, but the tone and expression are always the same. Karl Urban, I take off my metaphorical hat to you.
Anyway, TOS Kirk/Spock! A lot of it is seriously delightful. A lot of it, by which I mean the fic from zines way back in the day that their authors have obligingly posted online, is delightful for anthropological reasons -- I just read a fic, for instance, in which Spock spends a lot of time agonizing over/analyzing his feelings, and realizes that he thinks of Jim as a friend in the sense that he is a comrade-in-arms and maybe something more, and I was sitting there going, "Spock, t'hy'la is in your vocabulary, why don't -- WAIT" and realized that the fic's publication date was 1979, the same year Roddenberry coined the term in the movie novelization. Dude. Guys, I read fic that is older than t'hy'la. *___*
(Reading TOS Kirk/Spock has an element of don't-think-about-pink-elephants to it, though. There is nothing quite like coming upon a sex scene and going "DON'T REMEMBER THAT IT'S WILLIAM SHATNER." Oh, Chris Pine, if only you were as interchangeable with Shatner in my head as Urban is with DeForest Kelley. My life would be much less full of horror.)
Lastly: this still! The one of Kirk clutching at Spock while they are no inches apart! And I think Spock is about to meld with Kirk or something? It crops up in vids a lot. But I do not know which episode it is from! Can anyone tell me? I would very much like to know.