A few contenders. Star Trek TNG and Star Trek DS9 are up there. I finished Breaking Bad recently and really liked that too. I think Lost would be number 1 however!
tng and ds9 are the only ones which are not an insult to intelligent people.
all other star trek stuff is just popcorn. voyager has its moments but is also already more on the brainless entertainment side.
and jj abrams put the final nail to the coffin.
for me as tv series junkie - the wire still sits on the throne.
side note for all who are not familiar with it. you have to be patient. it unfolds very slowly and you might feel the tendency to quit after a few episodes. but maybe this is less of an issue than 10 years ago cause slow storytelling got more common.
this description is a mix of something i read somewhere and own thoughts which describes pretty well the amplitude of these three tv shows imo:
- breaking bad is a psychogram of a person.
- sopranos is a psychogram of a group.
- the wire is a psychogram of a city.