Anime Couples...

I want to see an anime couple that knocks my socks off. Or however you want to put it.

So, I'm asking for suggestions, if anyone has any. What anime couples do you really feel strongly about, from which series? Doesn't matter if it's yaoi, yuri or het. If I haven't seen it, maybe I'll give it a try! I want something that can make my heart race to watch! It doesn't have to be a romance anime or anything, I just want something with a pairing that'll get me really interested.

On an unrelated note, this is a really pretty song despite the fact that the anime doesn't look like something I'd like.