Nostalgia and TV are a tough mix. We all love the shows we enjoyed when we were growing up. Revisiting them can be fun if you watch a few YouTube clips, but start watching entire episodes of 70's and 80's TV shows, and you may find yourself laughing and waiting for it to end.
Not many TV shows have a high re-experience value.
I think Magnum P.I. is the exception to the rule. While I enjoyed CSI and Law & Order in the day, I don't ever want to re-watch them. Seeing endless stories of violent acts and the procedure in which they are solved is no longer entertaining to me. I'm not looking for sitcoms - they are too slow for me - but I also don't want to be entertained by content that is too dark.
Magnum P.I. is at its core a mystery show. This lets the story go all over - from missing treasures to missing people to whodunnit to fast action and even violence. The story lines were a mix of all of the above - from heavy to light.
And the characters.. All 4 main characters were much more likable than the guys from other TV shows that I enjoyed - Miami Vice and NYPD Blue (though that show was also a classic in so many ways - but I don't want to re-watch a police-based TV show).
Magnum was the adult we kinda wanted to be like as teenagers.
Higgins was the best supporting actor role in any TV series. The work of a legend. This character is so much fun to watch.
TC and Rick were "normal, cool guys" who knew how to go on adventures.
You can see the arc of the relationships between the characters. When Higgins stands up and shakes TC's hands in the last season..
Perhaps the most interesting episode guest starred Frank Sinatra in his last credited TV performance!
If you're looking for a fun to watch 80's TV show, try Magnum P.I.