Godzilla: The Planet Eater closes out the anime trilogy, and is the best film of the lot to boot. Without giving too much away, it does a decent job of explaining all the vagaries of the plot while brining everything to a conclusion.
It’s hard to talk about the details of the plot without giving things away, but I do want to talk a bit about Ghidorah (it’s no surprise he’s the new monster this time). Rather than being a flying, three-headed dragon, he’s a weird extradimensional entity manifested as glowing golden snakes emerging from dimensional rifts, and the laws of physics break down in his proximity. There’s a sequence that reminds me of End of Evangelion, as characters rushedly describe the distortion of reality, only for time to break down and they get a report of their own deaths before it happens.
The overall conclusion of the saga is a bit trite, but everything that builds up to it is great. Definitely worth checking out.