Supernatural - one of the best TV series ever made. I don't know why it is so great (Dean of course) but it is as good now (when I am watching it again from the beginning for the second time) as it was all the way back in 2005 when I watched for the first time. Only then I had to wait all week to see it and now I can watch the whole season in two days (with a little break for my work).
I cannot decide who is my favorite character (Dean of course) because they are all so great, complex, funny and entertaining. Every episode brings something new and the whole series is well connected by Dean and Sam, who not only are the main characters but also the soul of the show.
Additionally, when you think that the series starts to settle then a new character is introduced. We have John Winchester, Bobby, Ellen and Jo, Ruby, Crowley, The devil and of course Castiel - (:
Ok. I am going back to watching now.