I grew up with Dr Who, Blakes 7, and Buck Rogers. Cheesy but fun. Battlestar Galactica wasn't available in our TV area so we had to watch it on a fuzzy black and white portable in my parents' bedroom with almost no signal. Only saw a handful of episodes. Having watched some more recently, Blakes 7 (ignoring the special effects) stands up the best but Dr Who has the most enduring charm.
Much oif my love of sci fi came from the action figures so Star Wars and the Black Hole was high on my list. Star Trek and Battlestar Galactica produced only very limited runs and I didn't ever consider customs in those days.
I preferred ensemble shows so Invaders was a bit repetitive. Thunderbirds and Space 1999, I loved. Tomorrow People and Logan's Run I can barely remember. I only saw one episode of Children of the Stones but it's burned into my brain forever. The Owl Service was incomprehensible to me at the time. The Phoenix and the Carpet was good fun. Who can forget Chocky? Battle of the Planets was AMAZING. Sapphire and Steel is ripe for a remake. The Fantastic Journey and Buster Crabbe serials were on every school holidays so I grew to love them.