As to the greatest series of all times, of course The Wire and The Sopranos must be mentioned, but one certain show tends to be missed out: Six Feet Under, which I believe is one of the most wholesome of all shows and it's got an angle that really every one can relate to, a normal, slightly dysfunctional family setting. It's been Michael C. Halls (Dexter) first major appearance, and it's so full of true emotions and wisdom, I can't recommend it enough.
This year I've come across two new series that raised the benchmarks in terms of absolute, merciless honesty, great writing and not-of-this-earth acting: Patrick Melrose (recently finished) and just now, Sharp Objects. A wide range of all sorts of unresolved, past family abuse and a more than unstable present for the protagonists, having to deal with very demanding matters.
A bit on the lighter side while still pretty deep: the latest Dirk Gently adaptation, co(?)-starring - once again - Elijah Wood. Truly mind boggling...