"Dr Who. This was the era of Tom Baker as the Doctor. Honestly, it was amazing. But there were other shows that were just plain goofy like The Goodies and Monkey. On the sci-fi front you had Blake's Seven, which was way ahead of its time in moral complexity. To this day, Avon is an amazing character."

Avon is indeed amazing. And it's no accident Terry Nation, the creator of Blake's Seven, was the author of what made Dr. Who a smash hit with his script for the second serial titled "The Daleks."

Just squeezing into the "1970s" in 1970 was ITC/ITV's UFO which was also great SF, I watched it a few years after in weekly syndication in the US. Didn't get a chance to watch the previously mentioned BBC shows until the 1980s.