Sephiroth World: Hell no.
Ultimecia World: Meh. Would have liked Edea better.
Jecht World: FFX fans are almost as bad as FFVII fans. Almost.
Shadowlord World: I like it but I worry it might be -too- popular and will become the Odin of FFXIV.
Exdeath World: I liked FFV but I would rather avoid the people who will pick it just because it has "Death" in it.
Emperor World: Too generic.
Gabranth World: My favorite FF, but not really my favorite boss.
Garland World: A classic game with a classic villain. Much 8-bit love here. Third pick.
Kefka World: I like it, but also worry it might get too crowded. Either way, someone who would pick Kefka is pretty cool in my book. Second pick behind Golbez.
Golbez World: My second favorite FF, and while I'd rather have Zemus/Zeromus since Golbez isn't really a boss (Seriously, they go with Ultimecia instead of Edea but Golbez instead of Zemus? WTF SE?), It's my first pick.