Last updated: 06/09/2020
The films on this list range from classic kaiju such as Godzilla, Rodan, Mothra and King Kong to Japanese serials to truly bizarre entries to modern box office gold/bombs, giant monsters all.
Some entries are unexpected and others I'd never heard of before. Not limited to one country or region of the world. It is as complete as I can make it with the research done. Listed chronologically by release date.
If anyone finds film(s) missing, just comment below and I'll add them at my earliest convenience.
I couldn't find entries for any of the following films on Letterboxd:
Ultraman, Ultraseven: Great Violent Monster Fight (1969)
Helluva Good Luck 2 (2001)