I've seen only scattered episodes of NCIS, but I have to say, re:

Tony/Ziva is a kind of relationship that usually I'd be rolling my eyes and gnashing my teeth over how it's interfering with team dynamics or how annoying it is that the female character needs to be paired off or how it's wasting screentime or whatever. Except that I'm not. I think it's partly because the show has been remarkably cagey about actually defining their relationship as UST or true love or possibly deep friendship (it plays more like really blatant subtext than actual text - more like slash than a standard het 'ship, really.

Yes yes yes. On all of that. I like Tony/Ziva much more than I would have ever expected to, for all the reasons you mentioned. Blatant-subtext, almost-like-slash het ships are always much more fun than blatant-whack-you-over-the-head-official-couple het ships. (I have a feeling I'm going to incite a massive wave of eye-rolling if I go into yet another Avengers-related digression at mfu_canteen, but Steed and Mrs. Peel are an excellent example.)

Also, re: your proffered drabbles...would you mind if I turned this into a meme of sorts and stole it? I'm in need of prompts myself.