I will admit that I watch too much TV but I have cut way back in recent years.

Currently, here's my "must see" list:

ER
The Office (those two are the only network shows I watch)
No Reservations with Anthony Bourdain
Cops (I watch WAY too much of this one, but I find it oddly hypnotic)
Cash Cab (my guilty pleasure)
Many shows on the Travel Channel, Food Network and TruTV
Family Guy (at least once every night)
And a couple of really out there cartoons on Adult Swim - Aqua Teen Hunger Force and Squidbillies (I am a strange person)

I was really into several of the HBO shows - The Sopranos and Six Feet Under especially, but unfortunately they are both over. I do still enjoy watching reruns. And some older shows that are in syndication now that I enjoy are Wings, Sanford & Son, The Jeffersons. Really wish TV Land would bring back Welcome Back Kotter and Barney Miller...