There are so many great Supernatural episodes out there that manage to tug at the heartstrings, but there's only one episode that Jensen Ackles deemed his absolute favorite. Considering that the show ran for 15 seasons and 327 episodes, there's no shortage of Winchester hunts to choose from. But Ackles' favorite episode, Season 7's "Death's Door," is easily the series' toughest hour — and having watched it live back in the day, I can fully understand why the actor would choose this haunting hour as his favorite. In case you may have forgotten (and how could you?), this is the episode where Bobby Singer (Jim Beaver) dies, and the show never got sadder.