Godzilla vs Kong 1962 version; the ending is a total cop-out, leaving it lazily ambiguous but hinting towards an illogical Kong win just to placate American audiences. Thank fuck the 2021 version corrects this.
Actually, times were very different back when they first clashed fists. Godzilla was fairly new at the time as opposed to, I guess I should say KING Kong (it's an important distinction), who's been around since the 1930's. This was also back when Godzilla was still portrayed as a destructive villain, so naturally, they'd want KING Kong to win. He wouldn't get his "face turn" until 2 years later with Ghidorah, the Three-Headed Monster.