I'll try to rank most of these. I should rewatch a couple (Matango, Mysterians) and I haven't seen Gorath or The Human Vapour, but I have a good grasp on the others.
Invasion of Astro-Monster
Mothra vs. Godzilla
King Kong vs. Godzilla
Battle in Outer Space
I thought I was gonna put Varan at the bottom, but even though that movie is a dull retread, BIOS left me feeling even a bit colder.
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