I didn't vote for one because both relationships have their merits.
In defense of Angel/Cordelia, when you take into account that their relationship wasn't supposed to be the greatestloveofalltimeOMG like Angel/Buffy, then it makes a lot of sense. Angel wasn't replacing Buffy, he was moving on - which is what people do, regardless of how much they loved the person they were with before. Can we really fault Angel for not being hung up on Buffy all his undead life? I mean, really. That just makes things boring.
Now, I'm not a retard and I KNOW Angel and Cordy never really got together, but they way they went about their courtship was completely different than Angel and Buffy's. It was more...real. More adult.
I really don't have a lot to say about Angel/Buffy that hasn't been said before - to me, the relationship has been beaten absolutely to DEATH and I could stand NEVER hearing about AngelandBuffysTRUELOVE4EVA ever. AGAIN. But since I'll never get my wish, I'll state the obvious: soulmates blahblah, true love blahblah, always belong to eachother blahblah.