Great for its time, but the 2008 version is superior
I watched this version and the 2008 remake back-to-back and was curious to determine which one was better. I'll have to go with the 2008 version because this 1951 version is too dated. Although Michael Rennie as Klaatu is arguably superior to Keanu Reeves, I like the fish-out-of-water approach Reeves took, sort of Spock-like. Basically, the 2008 version took everything about this version and made it better: color, drama, f/x, Gort, the biblical typology and the spectacular apocalyptic climax.
That said, this '51 version was great for its time and is definitely worth catching or owning. It has a nice eerie 50's sci-fi score.
Although some parts are just lame and boring, I found it interesting to see how the USA was back in 1950, the way people dressed and talked, etc. Other than that, though, the 2008 version is leagues superior in every conceivable way. Unless you're thoroughly tainted by nostalgia, it's the simple truth. Maybe YOU CAN'T HANDLE THE TRUTH.