Forbidden Planet, starring Walter Pidgeon, Anne Francis and Leslie Nielsen, is available on DVD and online from googlevideo:
The video has an introduction from The Cinemated Man, and the movie itself starts at about 8 minutes in.
Forbidden Planet is the 1956 science fiction film which introduced Robbie the Robot.
There are Star Trek connections, some of which are explored here and some here.
Moria gives it high marks, calling it "unquestionably one of the all-time science-fiction classics". 1000 Misspent Hours says it's "a top contender for the title of The Ultimate 1950’s Science Fiction Movie". SciFi.com closes its review by saying that "the bulk of this film has aged well through the decades, largely because it can still invoke wonder...no mean feat." DVDJournal claims that "Now fifty years on, Forbidden Planet is still the best original spaceships-rayguns-and-alien-worlds movie Hollywood has produced." 1001 Flicks has a review.
3/14/2010: SFSignal has this film as their Sunday Cinema offering for today.