KING KONG VS. GODZILLA (1963; which I recall having rated BOMB) had been my introduction to cult director Honda's work; this one isn't necessarily better it's just that I've learned to be more tolerant towards such intrinsically lowbrow fare!
Here, we actually get two Kongs for the price of one: an ugly and dopey-looking giant ape and a robot variation of it which looks even worse! The simian creature lives on the island of Mondo(!) where it's shown fighting a couple of other monsters, and befriends a trio of humans. Naturally, it falls for the blonde (and bland) heroine; in fact, more intriguing is a femme fatale in cahoots with the film's villainous mad genius called Dr. Who and sporting the anemic look and cape usually associated with a vampire!!
He kidnaps King Kong and hypnotizes it in order to retrieve the Element X, which is embedded in the icy wastes of the North Pole; apparently, the giant ape is more impervious to radiation than its mechanical counterpart (and, to ensure its full co-operation, Who even captures its three 'companions')! The female agent then has a change of heart, helps the heroes (one of whom, typically, is a nondescript American) and is killed by Who. Kong eventually escapes and makes it to Tokyo, where it has a final showdown with the robot. The doctor flees the ensuing mayhem in his sub which, on a request by Kong's dreamgirl, is summarily trashed by the giant ape.