I was a rather well read teenager at the time of "Space: 1999" and the very premise of the show insulted my intelligence...that nuclear waste could "explode" and with enough force to not only break the moon away from the earth (without simultaneously destroying it) but for it to leave the solar system and somehow travel through the galaxy at better than relativistic speeds so that the crew could somehow visit lots and lots of other planets and somehow have time to do anything besides wave as they went by. Not to mention how expensive it would be to ship nuclear waste to the moon. Not to mention what a lack of tides would do to the Earth. Sorry, but I could never get past that particular bit of nonsense. And after that it was sort of like a rehash of "Lost In Space."
"UFO" on the other hand, was (slightly) more believable as an incredibly hyper paranoid show about alien invaders who are prevented from taking over Earth by a weird looking British guy who (as a cover) ran a movie studio. Plus, the moon chicks were hot with their hair and outfits. The whole concept of a completely secret organization that had a totally secret moon base plus all kinds of other alien hunting/killing equipment was a much more enjoyable diversion for me.
And when I was much younger there was the incredibly ridiculous "Thunderbirds" show with a super secret island base that does battle with a sinister madman. The model work was way ahead of its time and the goofy marionettes were about as state-of-the-art as you could get without going animated...which would not have been the same. It just looked more "real" the way that Anderson did it. I think that's one of the reasons that I enjoyed the hilariously off color and irreverent "Team America-World Police" movie that the "South Park" guys put out...it reminded me of the Anderson puppet shows.
Thunderbirds TV Show Intro (http://www.youtube.com/watch?v=BfIAKj3Gl1E#)
UFO - Opening Sequence (http://www.youtube.com/watch?v=0XAIXP937Ac#)
Pretty funny how a teletype was state-of-the-art computer interface, eh?
Space 1999 opening credits (http://www.youtube.com/watch?v=09BzitMkUCw#)
And, BTW...there seem to be lots and lots of complete episodes of "Space: 1999" available on youtube if you are so inclined.