I don't watch a lot of TV, primarily because of the sheer amount of crap that's on it. The shows I watch are usually ones on DVD that aren't being made anymore. Stargate SG-1 is one show I have all the DVDs for, as well as Red Dwarf which is one of the few comedy shows that doesn't get old no matter how many times you watch it. I even went back and watched the orginal 1978 Battlestar Galactica series which was cheesy and dated but still very entertaining. I cannot say the same for the reimagined series, which went downhill during its 3rd season.
One show I did watch more recently was the first season of the 1988 "War of the Worlds" television series. That was surprisingly good, despite being 80s cheese.