These two Ghidorah against Godzilla

Well, since Grand King Ghidorah is King Ghidorah (only the American copy adds the "Grand" part), I would have to go with the former.

I would like see King Ghidorah, rather than just any Ghidorah.

Probably King Ghidorah, deathGhidorah whas killed by leo mothra, while King Ghidorah whas killed by superior armor mothra

Desghidorah. I like his design more and it would be more interesting since the other one looks exactly like King Ghidorah, I'd like some variety.

i prefer desghidorah

I prefer DesGhidorah's design, but GKG would be a better opponent for Godzilla.

All "Grand" King Ghidorah is is a smaller version of King Ghidorah, who Godzilla has already beaten numerous times. At least Desghidorah is an opponent Godzilla hasn't fought, but even so Godzilla would probably still handle him.