Personally I like FlutterMac better because their personalities match up better than with RariMac.

Yeah, FlutterMac is much better.

Plus Rarity seems to only really be interested in high-class ponies, so unless a fic really developed a relationship between her and Big Mac I'd say Fancy PantsxRarity is more likely.

I always thought Fancy Pants X Picture Perfect :tehe:

I don't ship anyone with Mac because I hate his guts.

I mean seriously if there's any reason to advocate homosexual pairings in MLP it might just be that the male characters are so darn insufferable. (Discord and Spike aside)