I've been a Godzilla fan my whole life. But in hindsight, every single Godzilla movie is unwatchably bad.
The first Godzilla movie I ever saw was Godzilla 1985: The Legend is Reborn (aka 1984 Gojira). But after a recent re-watching, it was a chore. The second Godzilla movie I ever saw was Godzilla's Revenge, and I remember really liking it a lot when I was little. But now? Good lord, is it terrible. The third Godzilla movie I saw was Godzilla VS The Sea Monster (Ebirah). It too is a terrible mess for me now. Throughout the years, I've seen Gojira (the original), Godzilla VS Biollante, Godzilla 2000, Godzilla GMK, Godzilla VS The Smog Monster, Godzilla VS Destroyah, Godzilla: Final Wars, Godzilla 1998 (American), and the original movie which introduces the Xillians - I forgot which movie that was.
The only one that has re-watch value is Godzilla 1998. I know that sounds like heresy, but it is the most balanced, well written of the Godzilla movies so far. The production values are good, the effects are good. It's far from perfect, and the third act with the babies drags it down severely.
Despite my general disdain for pretty much every Godzilla movie, I still consider myself a huge fan. To me Godzilla represents a mysterious power that wants to be left alone. He's something awesome with a lot of potential, but none of the movies have been done right. I'm a fan of Godzilla, but not a fan of his movies. I don't think any of my other fandoms work this way, but Godzilla does.