hmmmm, this is a very tough choice to make, heres how I see the choices
KG: he has the original "spirit" of KG with a nice, ferocious, updated design, but he doesn't have that crazy, insane space kaiju look about him that strikes fear into his opponents
Mothra: I didn't like the idea of giving Mothra beams and the more fuzzy look, so shes out IMHO
MG: I liked the design, but in gaining a high tech look, he lost his original meanicing touch, so he's not it...
Mog: I like the design, but...not enough to give him my vote
Baby G: I really like the idea of bringing back a "son" for Godzilla, but I consider Minya a totally different species than Godzilla, a poor sad creature Godzilla found on the island and decided to take care of, so I don't see BabyG as an update
Rodan: another update I was impressed with, just as much as KG, I loved his new design and Angurius-esque attitude
so, Rodan and KG tie for me, both great updates, Ill vote for KG though...
-Emkaiju