I'm nearly 30 so from now on I need to make sure not a second is wasted in every leisure activity. So let's sort the wheat from the chaff.
My two pennies worth (predictable but oh well):
Boardwalk Empire (some episodes take a while to catch fire though)
Twin Peaks (but cutting out most of the second half of the second season)
Breaking Bad (but with every scene including Skylar deleted and replaced by relaxing pan pipe music)
Also feel free to name every TV boxset "not" worth watching.