Board Thread:Monster Discussions/@comment-4851935-20140209154830/@comment-6580055-20140212000417

I'd say:

SpaceGodzilla.

MechaGodzilla.

All Ghidorahs (Keizer Ghidorah, Mecha King Ghidorah)

Destoroyah (Godzilla must hate him, he killed his son)

Biollante

Gigan

Maybe Zilla(troll).