Often, key moments in our lives are only recognized as such in reflection. This is no different when we're talking about great television. My own TV-viewing years only began in the '80s (and were interrupted by a couple years overseas, where television basically sucks, USA, USA, USA!!) but with access to old shows and old TV-schedules I can judge what would have been ideal seasons for prime time lineups. Here are my top candidates:
1) 1972--shows like "All in the Family", "MASH", "Odd Couple" and "Mary Tyler Moore" were all at their peak. These were the years of the classic sitcom, multi-camera, laugh track, setup-joke-repeat, all the key elements that lasted well into the '90s (and still exist on some shows today). Mid-Nixon era was a golden age for television.
2) 1977--this was a turning point year, the "jiggle year" for television, where "Charlies Angels" and "Threes Company" got their start, and blond, big breasted women were all the rage and network standards were challenged. Of course, the actual shows were low-quality at the time. "Threes Company" (which I admit to LOVING as a kid when it was in syndication) was one long gag of someone eavesdropping and misunderstanding what they hear. "All in the Family" was rapidly going downhill and taking the funny with it. "Mary Tyler Moore" finished up, and "Good Times" was one long "Dy-no-mite!" joke. It would be another year to wait for "Taxi", and while "Welcome Back Kotter" was on the air, it was distinctly lacking Vinnie Barbarino because Travolta was a movie star by then.
3) 1989--this was another turning point year. The new "Fox" network was in its third season, and by this time had a lot more shows (as it was broadcasting original content on more nights). Fox was great--as the number four network, they could take more risks, and "Married With Children"--one of those risks--was hitting its stride. An adult cartoon show called "The Simpsons" premeired that season, and is still on the air today. "21 Jump Street" was at its high point, and featured a then-unknown Johnny Depp. "Cheers" was showing signs of decline, though, and "Mr. Belvedere" and "Growing Pains" proved that ABC had a crappy lineup, though "Roseanne" was still good at this time. The '80s basically sucked for television (unless you like awful soaps), but the end of the decade showed promise for the next one.
4) 1993--this was a solid year. "Simpsons" was hitting its stride, "Conan O'Brien" debuted as the funniest thing on late night, "Seinfeld" was having one of its best seasons, and "Frasier" started out, keeping up the quality of the best years of Cheers. You could also still sometimes see music videos on MTV, which I'd watch at friends' houses since my folks wouldn't get cable.
5) 1995--the '90s were a new golden age of sitcoms! "Seinfeld" was still strong, in fact, strong enough to anchor whatever NBC wanted to put on before or after it on "Must See TV" Thursdays. (Forgettable shows helped by Seinfeld--"The Single Guy", "Union Square", "Fired Up", "Caroline in the City", "Veronica's Closet", that thing Brooke Shields was in). Also, "Drew Carey Show", "Friends" (which had its moments), "Spin City", "Everyone Loves Raymond", "King of the Hill" and "NewsRadio" were all on the air at this time. The "Simpsons" were firmly entrenched on Fox (I'd been afraid it'd be cancelled for low ratings in its early seasons) as well. 1995 was shaped up to be a lot like 1972--a golden year for the classic sitcom. Notice also that a large number of sitcoms were given to standup comedians--Drew Carey, Roseanne Barr, Brett Butler, Jerry Seinfeld, etc. If you had a standup act, ABC had a slot for you!
6) 1998--by the end of the '90s, cable channels were putting out a lot of their own original content. HBO (which should show movies, but basically is to movies what MTV is to music videos) had "Larry Sanders" and now was debuting "Sopranos", the great mafia drama, and Comedy Central was showing "South Park", the great poorly animated cartoon. While some argue that "Simpsons" was declining, they still had some great episodes at this time, as did fellow Fox cartoons "Family Guy" and "King of the Hill". "Frasier" was still strong, though "Seinfeld" went off the air, as did "NewsRadio". "Drew Carey" was getting experimental by this point, "Married With Children" was allowed to die its slow death, as did "Roseanne" which I wasn't watching by this point because it got too weird. TV was still strong then, but the traditional sitcoms were giving way to single camera fare with no laugh tracks, and cartoon shows were gradually taking over Fox's Sunday lineup.
7) It's hard to pick a single year for the last decade--great shows did come and go ("Arrested Development", "Freaks and Geeks", "LOST") but it's hard to pick a single year that stood out from the rest. While TV arguably got very awesome--and I think this is simply due to the massive competition unheard of in the old days of only three channels--there were also some awful trends that are still with us (mainly I'm thinking of reality television). Nowadays, a laugh track multi-camera sitcom seems quaint (even on top rated shows like "Two and a Half Men"), and great experimental fare of teh semi-mockumentary sort ("Modern Family", "The Office") and quick cuts made popular in "Scrubs" are standard (see, "30 Rock"). But most important is the fact that you can see just about anything online or via DVD, so you aren't stuck with network timetables. This also means you can see every episode of a show, not missing a single one.
8) You'll notice I left out the '50s and '60s--not a knock on those decades, only I haven't seen many of those old shows so it's hard to judge. The '80s generally sucked for television, though we didn't know it at the time so we laughed at "Silver Spoons" and "Diff'rent Strokes" because we didn't know better.