The Simpsons, 30 Rock, The Office, Parks and Recreation are all very smart and very funny.
Lost is an intriguing network drama, has any other show really broached the topic of multiple planes of existence?
Cable has a number of dramas and comedy dramas that are well worth watching…Weeds, Curb Your Enthusiasm, Dexter, Breaking Bad and Mad Men
I still find engaging programming on the History Channel, TLC, Discovery, etc., like The Universe, How It’s Made, and Life After People.
I watch other things that are definitely not worthy of my intelligence (Family Guy, Cleveland Show, American Dad, South Park, Desperate Housewives, Nip/Tuck, Glee) but which are at least well written and ably performed and provide enough escapism that I can retain enough mental energy to enjoy my highbrow TV tastes as well.