Early Rentaghost was absolutely brill!
After having to endure the Wanderly Wagon DVD recently I can only thank my lucky stars that the BBC and the various ITV companies were able to produce stuff like this Rentaghost, Tomorrow People, Blue Peter, Magpie etc rather than the tripe RTE produced then (and to a large extent now).
I was trying to remember this other kids programme that was on when I was a nipper about a plague of some sort that wiped out all the adults and left only the kids. It used Mike Oldfield's Tubular Bells as the theme and incidental music.
There was an adult oriented programme in a similar vein that ran some time in the mid-seventies about a virus that accedentally escaped in a lab somewhere abroad and was then set loose into the broader population when the scientist who had caused the original accident tried to escape and died in Heathrow. Can't recall what that was called either but it was completely enthralling at the time...maybe I'll try and find it on the hinterweb...