There was only one, "Godzilla vs. Megalon". Arguably one of the weakest entries in the franchise, the movie was scripted to showcase Jet Jaguar with the hopes of developing a television series from it, similar in concept to "UltraMan". (Certainly the production values looked more on par with a "budgeted" TV series rather than a motion picture. I've read debated discussions that Godzilla was written into the the story at a later stage simply to attract more viewers. Supposedly, he was not originally part of it.
Even if you haven't seen the movie itself, you've possibly seen a rather (in)famous clip of Godzilla performing a crazy "running drop kick" during which he just kinda' slides upon his tail as his body hangs in a rigid horizontal position, his feet finally slamming into the beetle inspired kaiju. Mystery Science Theater 3000 used to play that shot during its opening credits.