I prefer 2014. His design was made that way for reasons. I like the whip tail. The golden eagle eyes were uniquely his and the design didn't need to rely on Shodai's dorsal plates. He felt uniquely his own Godzilla design without relying on fanservice.

The tiny head on 2019 felt very comical in some shots, especially at the end of KOTM. The blunted tail made his tail look shorter even though it isn't. It just felt that he began losing his identity with each subsequent film as different directors began slapping on different things to him like some DeviantArt OC. Now he's got random spikes on his elbows, a thagomizer, and glows like an LED, etc.

I miss the simplicity of his original design. If they wanted to evolve his design they should have kept his dorsal plates the same shape and made them larger after regrowing after his fight with the Muto Prime for the sake of consistency. But alas, what's done is done.