Sanda (サンダ) & Gaira (ガイラ)
With their humanoid design, Gaira and Sanda are unique in the world of kaijū cinema. They have distinct personalities, making them far more interesting than your average destructive force of nature.
Manda (マンダ)
The concept of Manda is cool, and there's no other monster in the Toho line-up like him, but to successfully pull off a snake-like dragon is obviously a difficult task, which perhaps explains his lacklustre appearances.
M.O.G.U.E.R.A. (モゲラ Mogera)
Though he's certainly no Mechagodzilla, I quite like Mogera. He poses little threat with his shrewish face and lumbering movements, but his design is impressive and refreshingly bizarre in both his iterations.
Rodan (ラドン Radon)
I've got quite the soft spot for Rodan. Invasion of the Astro Monster the first Godzilla sequel I ever watched and helped spawn my obsession with kaijū cinema.
Toho’s King Kong (キングコング Kingu Kongu)
King Kong works better as a stop-motion creation rather than a man in a suit, or at least the suit Toho used. But there's an undeniable charm to Toho's Kingu Kongu. It's hard not to take some pleasure from that frozen expression of joy on his mangy face.
The Gappa Family (ガッパ)
It's a shame Nikkatsu only made this single kaijū film. Gappa, while no masterpiece, has a lot more energy and passion than some of the Godzilla and Gamera efforts that appeared towards the end of the Shōwa era.
Bemlar (ベムラー Bemurā)
Bemlar may not be Ultraman's most exciting adversary, but, in the Ultra series history books, he is perhaps the most important one. Bemlar is the first giant monster to have the living snot beaten out of him by Japan's favourite Protector of Earth and Slaughterer of Mindless Monsters.
Ebirah (エビラ Ebira)
Most Godzilla adversaries are very alien and fantastical in design. King Ghidorah is a three-headed, laser-beam-firing dragon. Hedorah is a giant slab of sludge. Mothra doesn't look like a moth. But Ebirah is a much more earthly monster. He's a giant lobster.
Zigra (ジグラ Jigura)
Zigra lacks the flat out weirdness of Guiron, the brutish panache of Gyaos, and the creepiness of Jiger, but he is still a fun foe. Zigra's convoluted scheme involves kidnapping a sexy spacewoman from the moon, interrupting radio programs with verbal threats, and crowning himself King of the Sea.
Jiger (ジャイガ Jaigā)
You know from the moment Jiger dredges her fucked up body from the earth that she is going to be a creep. In Gamera vs. Jiger, Jiger does something to Gamera that is the worst thing I've ever seen a giant monster do to another giant monster.
Guiron (ギロン Giron)
Goddamn. I love Guiron. He should have got his own spin-off movie. Although it would probably just be torture porn of him chopping up Space Gyaos.