Not easy... I'd feel like I'm messing with the girl's feelings. =[lol uhhh.. wow, some people take pairing really seriously. I'll never understand why people equate pairing with being in a real relationship. o__o; It's just for fun, people.
But yeah, I'd pick my current pair (Sylphiel) if anyone on PC to be paired with. Other than that, Lightning, Josephine, Aegis are others I'd be cool with being paired with.
I'd pair up with a guy for fun though =P