As canon pairings:
-FangxVanille
-SnowxSerah (for obvious reasons)
Now my own crack theories:
-Jihl and Galenth (I might be the only one who sees her as the kind of woman who beds her boss, so it wouldn't be anything romantic)
-YaagxLightning (And I might be also the only one who thinks that these two might have ended up together if Lightning had entered PSICOM. I mean, Yaag is a good guy after all,
and "Cloud face" always matchs with "silver haired dude" .)
-RygdeaxFang (Though onesided on the part of Rygdea)