For me, personally, I tend toward 'ships that evolve over time. The best friends that eventually fall in love.......Mulder/Scully, Luke/Lorelai, and Angel/Cordy
(of course). There's just something so romantic about that to me, I don't know why. I guess because I don't believe in love-at-first-sight and I think that the lasting relationships are first built on friendship and trust. I know, I'm a sap.