I chose Angel/Darla because it's what works best for me in canon. He's evil, she's evil, they do evil things together. For me, it just works. But I don't care one whit.

I'd really have loved for Cordy/Angel to have worked, though. It's a shame they screwed that one up so badly because I really think it could have made me actually like Angel. Most of my favorite Angel moments have to do with him being dorky, and I think Cordy could have brought that out in him. (Of course, I mostly contribute Angel's dorkiness to DB. I don't think the writers or Joss even think of it as a character trait for him. The Manilow thing feels more like a dig at the character than a truly dorky trait of his.)