As I think almost everyone knows-- my favourite ship is STILL Buffy/Angel. It was the first ship I was a fan of, the center of first fanfic I got serious about writing, the pairing in 90% of any fanfiction I read, and I still love the characters. I think it was a very real-to-life relationship for Buffy's age (right down to the part that it didn't work out), and although the characters don't officially get back together, I like to think that if the show continued, they would eventually. Think there's just no other way for it to go.
Also a fan of...
Faith/Spike
Giles/Joyce
Tara/Willow
Xander/Anya
🙂
And I love Buffy/Spike as friends, think they became very close, very dear friends in the end. But don't like them romantically involved.