Gigan is a cool monster, but his first movie is probably the poorest Godzilla movie ever made. it's a wannabe Ishiro Honda movie instead of a a regular Jun Fukuda movie, like Godzilla vs Megalon is. I've come to like it more these days. when Gigan was finally revisited in FINAL WARS he got an updated look, though not really an improvement.
and gets slaughtered twice in the movie. I almost feel sorry for the beast. he's a little less cowardly in FINAL WARS, but it makes no difference.