These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
YMMV: Ghidorah The Three Headed Monster
Anti-Villain: Since Godzilla states that he only hates humans because humans hate him, this implies he's not really a villain in the first place.
Broken Base: In America, fans are divided over which is the best Ghidorah, and it generally comes down to 3 of them- The Heisei Ghidorah, the Ghidorah from Rebirth Of Mothra 3, and the original which features in this film.
Complete Monster: Among kaiju, King Ghidorah is probably the worst of the complete monsters, totally insane, going around killing worlds just for the heck of it, and laughing like a maniac all the way through. However, this is one of only 2 times Ghidorah is actually a Complete Monster- the other time would be in Rebirth of Mothra 3, where ironically King Ghidorah battled not Godzilla but Mothra, but was perhaps an even greater Complete Monster. Every other time, King Ghidorah has been but an alien pet- or in one case, The Hero.
Ear Worm: The aforementioned Ifukube soundtrack, but particularly March of the Monsters.
Subverted as the second Ghidorah movie, Invasion Of Astro Monster, is considered by many to be as good if not better than Three Headed Monster.
Averted in the context of the series where the original Gojira is still considered the greatest of all, even if GTTHM is a popular entry in the series.
Moment Of Awesome: The Battle Royale at the finale is awesome (even if it is a little too goofy at times) and is still among the most iconic battles in Kaiju eiga and a turning point in the development of Godzilla himself.
The sequence where King Ghidorah devastates Tokyo is also great stuff and makes very other scene of city destruction before it (and most after) look like a picnic- nothing has been quite as grand
And of course, Rodan vs Godzilla, where the pterosaur actually goes toe to toe with the King of the Monsters.
And when Mothra convinces them both to get their heads out of their asses and battle King Ghidorah.
Narm: When Ghidorah causes a rockslide that kills Malmess, he... catches a giant rock, then falls to his death.
The English version, dubbed by a-Bellucci Productions!, while praised by some, has its fair share of narmy lines, many delivered by the princess.
"I think that bracelets are worthless and silly. If I had one, I'd give it away immediately."
Narm Charm: Rodan throwing rocks at King Ghidorah to defeat the Eldritch Abomination is goofy as heck but somehow awesome.
Nightmare Fuel: Falls under fridge, but it might as well be noted here. Another troper noted on the main Godzilla Fridge page that the first Mothra Larva mysteriously disappeared, and in the previous film Godzilla appeared interested in consuming the Mothra egg. I think we can add things up from here...
Perhaps even creepier, catterpillars will actually consume their own if they don't have enough food. In the previous film, Mothra vs Godzilla, it is mentined that if the Mothra Larva hatches it will consume much of the Earth's vegetation (the previous Mothra is likely very, very old, a Larva back when its huge appetite was hardly a problem). Now that TWO Mothra Larvae have hatched, Birth Island is clearly not a flourishing garden, ans Earth is clearly not consumed, the implications could be horrifying.
Squick: Rodan drops Godzilla crotch first onto an electric tower.
Ugly Cute: Mothra Larva, and in a sense, Godzilla.