How about Glen Hansard and Marketa Irglova from Once? I’m only calling them that because, as far as I recall (and IMDB confirms) the characters are never named.
It was a short relationship, to be sure, but powerfully emotional.
Moonlighting’s David & Maddie. GREAT until the pregnant lady was rolling on the floor with the guy with a broken shoulder.
My problem with Mal & Zoe isn’t that it isn’t close. It’s that it’s not PRIMARY. Zoe’s affection for Mal was a faint breeze compared to the gale of her love for Wash.
The username GoodOmens reminds me of Crowley and Aziraphale. 
Although Anathema mistakes them for a gay couple and Aziraphale in particular comes across as gay to mortals, their very VERY long-term relationship is presumably sexless. We are specifically told by the narrator that angels don’t have sex.
Chell/Companion cube
I believe the exact term is “gayer than a treeful of monkeys on nitrous oxide”, which is, face it, pretty gay.
Oooh, I have one - Marty Crane and Eddie.