To continue (sort of) the theme of disappointing movie endings, how about films which are brilliant for about the first 3 minutes, then go rapidly downhill.
I'm thinking of things like Van Helsing (the brilliant monster movie pastiche of the opening giving way to a make-it-up-as-you-go-along plot with dodgy cgi), or Hellboy.
I'm thinking of things like Van Helsing (the brilliant monster movie pastiche of the opening giving way to a make-it-up-as-you-go-along plot with dodgy cgi), or Hellboy.