>>7690991Here is a chart I ran into awhile ago that seems to help people.
The best place to start is always the original Godzilla since its always the start of any new movie outside of the American movies and Shin.
From there you could continue with the Showa films to see some monsters first appearances or go to Heisei.
Heisei gets a lot of shit but, unlike the Showa movies, it's a small contained series which keeps a consistent quality.
As for Millienlium films they are very much "pick and choose" since they are all mostly disconnected and it'll depend on what you're looking for.