Gojira (1954)

 That's right, it's the often imitated, unmistakable, original smash-Tokyo movie.  When a monster has been on film pretty much constantly over 60 years, you know it's got to be good.

This is the gold standard for non-supernatural monster movies.  Sure, it's horribly dated and the production values sucked but it is a bonafide classic and you just can't argue with that.

There is a plot to it involving a scarred scientist, a dainty woman, and a scrap metal salvage specialist in a love triangle but who gives a good goddamn about any of that?

GODZILLA!  That's the star of the movie and that's who you're waiting to see.  And wait you do, my friends.  First he teases you with some wrecked ships and glowing water, then there's a footprint and some trilobites.  You have to be committed to this movie before it lets you take a peek under its skirts. 

The monster goes through a sock puppet phase before evolving into what is clearly a man in a suit and yet somehow manages to be charming instead of irritating.  The end is complete shit, though, with the biggest deus ex machina "solution" you've ever seen.  It makes about as much sense as a chocolate tea kettle.  But that's part of what makes it a masterpiece.  Even though you know it's crap, it still captures the imagination.  This is a great idea let down by the production values of the time.  That's why they're still churning out sequels and why Godzilla has changed from Scourge to National Hero.  He may have started out as a metaphor for nuclear disarmament but the Japanese knew they were on to a winner and we can all be grateful for that.