At first place, of course I love Sakura & Syaoran.
They're the best
I also loves couples from MKR: Fuu & Felio, Umi & Ascott, and Hikaru & Lantis.
I love Hikaru & Lantis mostly.
The manga and anime have different endings for their relationship though.
I like the anime version better
And then Misaki & Kotarou from Angelic Layer.
The manga and anime also have different endings for their relationship.
I like the manga version better for this couple.
Then Ashura & Yasha from RG Veda.
Haven't read all the manga yet, but I think they're cool.
I also love Akira & Utako from 20 Mensou ni Onegai ("Please, 20 Masks" or "The Thief of Many Faces", if I'm not mistaken) and Clamp School Detectives.
Sometimes I think it's a bit weird, since they're only elementary school & kindergarten students
But hey, it's CLAMP right?
It's weird but also it's somewhat kawaii...