This was my first contact with a SciFi show and my favorite as a kid. I had an Eagle model and build myself a Comlock and a Stun Gun out of Lego. I must have been 8 or 9 years old.
The production value, thanks to the Andersons, was really good. It looked absolutly believable. Yeah, the science isn´t waterproof but this was the 70s. You got away with a lot. The second season was not as good as the first (I remember some really ridiculous space monsters). They tried to americanise it by implementing tons of changes that just didn´t work out with the established facts of the first season. And those changes were also not explained during the shows second year. It became a different show.
All things considered this show is called a classic for a reason. As a fan of sci-fi you should have watched this at least once.