Series that I have watched - when they were on for the first time - are:
Blake's 7, Incredible Hulk, Six Million Dollar Man, Bionic Woman, The Tomorrow People, Sapphire & Steel, Space 1999, Hitchhikers Guide to the Galaxy, Star Trek (in all its guises, although I only saw the original series as repeats), Quantum Leap, Sliders, ReGenesis, Red Dwarf, Hyperdrive...I'm running out now, and they're not necessarily in that order, chronologically, but you get the gist.
I also love Gerry Anderson but had to watch all his Supermarionation series as repeats because I simply wasn't born when they were first shown (don't think I was anyway)
After Doctor Who, my second favourite sci-fi series of all time has to be Hitchhikers, but I loathed the recent movie. Its only saving grace was the wonderful voice of Stephen Fry as The Book. Beyond that, it was just embarassing to watch.
Yeah, fair play, geek alert.