The only straight ship that comes to my mind is Levi Ackerman and Hanji Zöe from attack on titan
Buffy X Angel !!!!!! Screw Spike!
HikaHaru from Ouran (I know she ended up with Tamaki, but still)
Minato X Subaru from Houkago no Pleides
Kyo X Tohru from Fruuba
There are others, but those three are the ones I immediately thought of.
My favorite one is definitely Tony x Ziva from NCIS ╥﹏╥
I suppose you mean unofficial ships? Then it's Heine x Naoto (Dogs: Bullets & Carnage -manga)
I mean, seriously, that scene in the church was hhhnnnh (okay I might be a little weird on that one)
I think I have some others but I can't remember XD
Who is/are your favourite straight pairing/s (from any type of media)?
Mine are:
Xiaoyin (from Tekken)
https://s-media-cache-ak0.pinimg.com/736x/46/84/b9/4684b93b6ecee06a982b8e1e8408b9f6--jin-kazama.jpg
And Zutara (Avatar: The Last Airbender)
http://img02.deviantart.net/0700/i/2015/144/3/1/10_with_animal_ears__zutara_by_artcrawl-d8ukiyd.jpg
These two are probably the last straight pairing standing on my list considering that I've been aboard their ship way before I discover yaoi; and now I don't ship straight pairings anymore (except these two)