Today's sci-fi thrillers are more like Rambo in outer-space with monster special effects (frequently ludicrous such as sounds of explosions in the vacuum of space). Though tame by today's standards, the special effects of "Forbidden Planet" were quite striking for their time. Even today, they still hold plausibility. Yet, the best part of the movie is perhaps the reason that radio thrillers still have appeal. Much of what was going on was left up to the imaginations of the audience. (What did the Krell creatures look like?) By having much of the framework of the story never divulged or only divulged in the end, the tension and suspense held throughout the movie. The ending was also very thought-provoking and satisfying. In my mind, this is still one of the best (if not the best) sci-fi films ever made.