
King Kong vs. Godzilla made in 1962 is the original battle of the titans. The title describes the film, there is no need to describe the plot.
KKvsG is a comedy, which surprised me. Yes there are super serious academics and Generals but the three central human characters take their acting cues from the "Three Stooges", if this sounds weird, it is. The big battle scenes between the monsters are hilarious and had me laughing out loud. I have no idea if that is what the director intended but once you put actors in rubber suits they automatically become funny.

As one would expect in a 1962 low budget film the acting is terrible and slows down the pace, you could skip to the last half but then you will miss the anticipation while thinking "will they ever fight or was I ripped off". I can't say the studio saved money on actors so they could spend lavishly on special effects either. The model making department was very busy, the tanks, trains and helicopters are from a model train layout, buildings are very crushable. Plenty of OMG moments that brought a appreciative smile.
The live giant octopus really was truly inspired and one of the highlights of the film:
"For the attack of the giant octopus, four live octopuses were used. They were forced to move among the miniature huts by having hot air blown onto them. After the filming of that scene was finished, three of the four octopuses were released. The fourth became special effects director Eiji Tsuburaya's dinner. These sequences were filmed on a miniature set outdoors on the Miura Coast. Along with the live animals, two rubber octopus props were built, with the larger one being covered with plastic wrap to simulate mucous. Some stop-motion tentacles were also created for the scene where the octopus grabs a native and tosses him. These sequences were shot indoors at Toho Studios."1
As in the original King Kong a young woman is captured, the realism is phenomenal.

King Kong and Godzilla also have a spa day together at the historical Atami Spa outside of Tokyo

The Atami Spa has been rebuilt after the battle as the Atami Hot Springs and Resort with beautiful views of Mt Fuji.
https://luxury-travel-japan.com/mt-fuji/
King Kong vs. Godzilla is the perfect lead in before watching the new Godzilla vs. Kong now streaming on HMO Max.
Watch the American trailer from 1962:
https://www.youtube.com/watch?v=QgmyQVKb1PoThe American release is slightly different than the original Japanese release, some scenes have been changed and it is dubbed in English. A free version is available on YouTube:
https://www.youtube.com/watch?v=2tD00QguKKY&feature=youtu.beCurrently the only way to watch a clean restored version of the original Japanese King Kong vs Godzilla is to buy the Criterion Blu-ray which is how I watched it.

- so bad it's good
1 The film's history and behind the scenes information is fascinating:
https://en.wikipedia.org/wiki/King_Kong_vs._Godzilla