When I was first introduced to Godzilla, I was probably five years old at the time and the only words I knew were names of dinosaurs. So when my parents gave me my first two movies, Godzilla: King Of The Monsters and Godzilla vs. Megalon, in a VHS box set I was curious after seeing a fire breathing dinosaur fighting a giant bug on the cover. After watching those two films, I was hooked and the rest is history. Now that I'm older and seen every single movie for the 15th-30th time in a row, I found Godzilla movies with a bigger budget and grew to like those more than the ones that were made in this era. My tastes in Godzilla movies not only changed, but most of the movies in the showa era were really not all that great.
It was because after King Kong vs Godzilla became a box office hit, it set the standard for the rest of the Godzilla movies in this series. TOHO saw money rolling in and told the producers to make more and UH-OH! The movies were making less money than usual, so TOHO had to cut the budget to save money. After Son Of Godzilla, TOHO initially just said, "Fuck it, we will make one more and end it all! Just throw in a bunch of monsters in and call it a day!" So Destroy All Monsters was made and guess what happened? It made a ton of money! By this point, they were probably happy that they gained a lot of money, but very confused at the same time. They had to be thinking, "Okay, why the hell did King Kong vs Godzilla and Destroy All Monsters work, but not any of the others?" So afterwards, they just didn't care anymore and they just let the series keep spiraling down-hill by just making them for children. It sort of worked when watching these with nostalgia glasses to remember my childhood, but in the end children is what most of these movies were meant for. Most of them are not bad movies at all. Some are just more or less over hyped.
Recommended:
Gojira/Godzilla: King Of The Monsters
Godzilla Raids Again
King Kong vs Godzilla
Mothra vs Godzilla
Ghidorah The Three Headed Monster
Godzilla vs Monster Zero
Destroy All Monsters
Godzilla vs MechaGodzilla
Terror Of MechaGodzilla
Watchable, But Not Recommended:
Godzilla vs Ebirah
Son Of Godzilla
Godzilla vs Hedorah
Godzilla vs Gigan
Godzilla vs Megalon
Don't Even Touch It:
Godzilla's Revenge