I remember enjoying Godzilla vs. Destroyah the last time I saw that film, and I've never gotten the chance to see Godzilla vs. Mechagodzilla 2, but I do agree with the other two on this list. I think I was really let down by Godzilla vs. King Ghidorah due to amount of praise it got from a lot of people. I'm sure that fans of this movie find a certain level of charm encompassed in its overly cheesy aspects, but it doesn't fully embrace those potential tongue-in-cheek qualities enough for me to find enjoyment in it. As for KotM, I have progressively become more and more opposed by that film with each subsequent viewing. It just doesn't do it for me, whether it's the poorly written characters, underdeveloped narrative, or even the tediously directed action sequences.
"What’s so great about discovery? It’s a violent, penetrative act that scars what it explores. What you call discovery, I call the rape of the natural world."
— Dr. Ian Malcolm, Jurassic Park (1993)