The next issue of Xenorama is going to examine that very question. It will feature every movie that Mothra has starred in. This does mean no cameo appearances will be talked about in depth but they may get mentioned.
I've already done most of the original series of movies. It's been fun to review them, because they are so much fun.
I've also gotten several really great reviews of the second series movies, including two different visions of the three film Mothra series of the 90s. Which is really great, since I don't remember them very well nor do I have them in my collection.
Pretty great captures, huh? Mothra really is a great character, I'm glad she's the second most popular Toho monster out there. Looks like the next issue will be done before the end of the year. Pretty cool huh?