For me, I really like zoro/nami pairing and that for many reasons :
They are both stubborn, they are both good drinker, their zodiac signs fits each other perfectly ( scorpion/cancer known as the most successful alliance , and we all know what do the zodiac signs mean to japanese, which means that Oda selected them carefully … :p )
Both of them have scars, their weapons are splited into 3 parts : zoro has 3 swords, and nami's climat tact has 3 parts
Nami is a cartographer, and zoro a "lost child" : how can the future world best swordman losts his way, he need someone who never losts ... :p
n japaese Nami is writen that way ナミ=> look carefuly :
ナ => na => looks almost like a katana _
ミ=> mi => which means three => zoro has 3 earings, 3 katanas and for nami, her climat tact has 3 parts and she loves number 3 ( look at the t-shirt that she wore at ennies lobby .... is that coincidence ?
and for luffy, there is that reason that let me think that he will be paired with Vivi : we all know that Oda's senpai is toriyama sama ... so he is a fan of DBZ ... chichi, goku's wife, sounds almost the same as vivi ( I mean the syllables ) chichi also used to be a princess ( she lived in a castle ) and goku helped her,same thing with luffy and vivi
I've also -kind of XDD - detected some Oda's hints in lots of his artworks ... I'll show you them later