the crotchety woman bailif is trying to get a husband to help his wife give birth. He passes out. The bailif says "Just like a man. When you want them up they're down, and when you want them down they're up." Classic.
When you get into "all time" shows you have to look at how it holds up in reruns. The best shows for that imo
Andy Griffith
Dick Van Dyke Show
Everybody Loves Raymond
Columbo
Of newer shows that might turn into classics
Entourage
Modern Family
Stargate SG1
Friends
Seinfeld's last show kind of ruined the show's legacy in that it pointed out how horrible those characters were as people. Now when I watch it I always think of that and don't like them.
MASH became too preachy especially when it became Alan Alda centered.