Finally got to watch "This Island Earth" a while back. Liked it but really didn't see why it should be classed as a Morningstarr* Classic...
Although the science fiction was credited as being good at the time, I don't think they really pushed any boundaries. Obviously, many of the techniques used are still very similar to those special effects used in movies today, just a little less polished. But I don't think This Island Earth can claim to have invented them...
The alien was a reject from It Came From Outer Space, according to the Wiki, which is quite believable - as the alien isn't

. It does look good, up to the point he clubs it over the head. It bounces around like a rubber tyre, and the sound, hee hee.
And as for the Metalunans, why the fook should we feel sorry for them being destroyed, they're a bunch of gits. They blow up a house filled with our brightest, possibly stunting out scientific growth for the next 100 years - if this was real, or course...
But that said, it is damn good fun, and just perfect for a parody. The scenes on the alien planet are all seriously cult iconic of that era - right done to the rubbery alien with an exposed brain.
Although I didn't see much merit in the film, I did love watching it...