I remember there was one episode that used to be featured in the video section of this page, but it's not there anymore.
All I know about it, apart from the fact that it was in black and white and seemingly involved Aliens, is that there's one scene when a helicopter is landing, and the MST3K gang is 'singing' the Ride of the Valkaries. It also featured the riff 'Hi, Steve'.
I know that's not much to go on, but I've been wanting to see that episode in its entirety. Thanks in advance.