6. In My Time of Dying- Season 2, Episode 1
After the shocking car accident at the end of season 1, season 2 picks up with Sam, Dean, and John rushed to the hospital. Dean's spirit wanders the hospital corridors. A reaper attempts to convince him to cross over. Meanwhile, Sam tries to save Dean and John summons the yellow eyed demon to a showdown. We are in season 8 now and this still remains one of the best episodes ever in the shows history. A lot of misdirection is used in this episode. First we think that Dean is perfectly fine but we find out he's a spirit. Then another spirit helping Dean is secretly a reaper. John summons the yellow eyed demon to the hospital. We think that John does that so he can kill the demon but he actually makes a deal with him. John sacrifices his life and soul so Dean can be brought back to life. He proves that he will do anything for his boys. He shut up anyone who believed he didn't love his sons. From that moment on, the show was changed forever.