Updated 8.29.10 - Mad Men climbs (I am only halfway thru the current season). Big Love drops majorly after a terrible, terrible season. Love Glee but hate American Idol-like autotune musical covers. Heroes last season was so bad I question whether they should stay even in the lower rings of this list. Had to move Survivor up a bit as well after a number of great seasons in a row after all these years.
Updated 2.10.10 - movement on the chart - Mad Men Season 3 sold me hook line and sinker. . . and Big Love this season has been a bit too over the top, hopefully it will reign itself back in... and this list has now basically become "Best TV shows of the Decade".
In my 20s i watched very little TV, and it's hard to compare old shows/shows i watched as a youth (when you are a bored kid, Charles Nelson Reilly on Match Game qualifies as entertainment) to current fare, so this isn't really an "alltime" list - but it's pretty close. i fear that the golden age of TV may have been approx 2000 - 2007 or so (mainly because HBO was on an unsustainable streak), but hopefully will be proven wrong. I did love a few shows in the 80s (St Elsewhere, Hill Street Blues, M*A*S*H) and early 90s (LA Law and Seinfeld), but honestly that is probably about it. I also find i have a hard time watching any show with a laugh track nowadays, which probably unfairly biases me towards the last 10 years of TV.
The reason the ratings are all clustered so high is because i am not listing the many shows i tried watching a few shows of and bailed on. So this list is basically every TV series I have watched at least a full season of since i got DirecTV, except perhaps for a few that i watched a season or so of and got cancelled to a level where I forgot.
I would also like to point out that a list like this brings up some general Ranking questions - for example, is it fair to combine cable shows (less episodes needed, more leeway with the sensors) with network shows. Should a show like The Simpsons - which I think very few longtime fans would disagree ain't what it used to be, but certainly doesn't suck - get punished because, well, they have done over 400 episodes, and they are bound to run out of ideas. Food for thought, eh?