Right now my favorite dramas are Breaking Bad, the Big C and Dexter. A few odd things about them:
1) In all three, the main character is hiding something from loved ones, family, or work.
2) Two of of three cancer is involved (Breaking Bad, Big C)
3) Two out of three involve breaking the law (Breaking Bad, Dexter)
4) Two out of three involve murder at times (Breaking Bad, Dexter)
5) Two out of three use dark humor to great effect. (Breaking Bad, Dexter)