
Oh God, I remember that one. If I had to choose one, it'd be X-files. It's tough because I absolutely love Battlestar Galactica(old and new) and there were so many great series that left an impression on me growing up. Shows like Andy Griffith, The Twilight Zone and Perry Mason, a bit before my time true but I watched the re-runs late every night with my granny after johnny Carson went off.
Air Wolf, Knight Rider, The A-Team, Manimal, Forever Knight, V, Simon and Simon, Magnum P.I., Alien Nation, Riptide, In the Heat of the Night, Blue Thunder, The Equalizer and so so many more. In fact, here's list of just the 80's shows most of wich I enjoyed very much. Other than Star Trek, SG-1/Atlantis, The X-files, Firefly, Dark Angel, The Dresden Files, Ghost Hunters, UFO Hunters and BSG I can't think of anything else that's even peeked my interest in the last fifteen years or so.
http://crazyabouttv.com/decades/1980s.html