This doesn't reflect what I considered to really be the highest quality shows of all time. It's just my favorites. These are in no particular order:
Buffy The Vampire Slayer
Daria
Psych
Golden Girls
All My Children
Pushing Daisies
Veronica Mars
Brooklyn Nine-Nine
Cheers
One Day At A Time
Honorable Mentions:
Happy Endings
Crazy Ex-Girlfriend
Playing House
Firefly
The Good Place