Had a discussion with my girlfriend, and we both talked about after the main show has finished, why not do John Winchester's story? From when he learnt about after Mary's death, to his own death. Bring back Bobby, Ellen even Daniel Elkins, Many fans have some unanswered questions about John's hunting history. What does everyone else think about this?
I know the CW is interested in a spin-off but I can't think of a single story I would watch. Jody & Donna might have been interesting but only without the kids. They've ruined Garth and killed off everyone else. Using a current character where the pickings are so slim will be difficult. Some have suggested Cole but the character hasn't inspired me in any way. Kevin would have been good but...
They need to leave out any angels altogether and I don't really like the idea of a monster story, Supernatural is about heroes and there are way too many monster-as-star shows out there and most of them suck.
And I agree with NolaNola, no prequels!
I still think Samuel Colt, cowboys and demons would be a fun spinoff. Especially if he was a snarky Indiana Jones type character. It would be a huge risk for the CW to air essentially a western from the 1800's but I would watch it.