I started watching Supernatural around 9-10 years old, and I really liked it.
I miss the original theme of episodes they did in the starting seasons, urban legends, different monsters, curses, etc.
It oddly went into religion territory, no quarrels, Castiel and Crowley are good characters.
On the bright side they have been doing more oddball ones, (Wizard of Oz/Fanclub/Larping/etc.), so that is interesting.
Overall though definitely my favorite characters are Death, Castiel, Balthazar, and Bobby.