Supernatural, Season 1, Episode 1 (Pilot)

Protagonists:  Introduces Sam Winchester (brother to Dean and Adam, Son to Mary and John), Introduces Dean Winchester (brother to Sam and Adam, Son to Mary and John), Introduces John Winchester in flashback (Father to Sam, Dean and Adam, Husband to Mary), Introduces Mary Winchester in flashback (Mother to Sam and Dean, Wife to John), Introduces Jessica Moore (Girlfriend to Sam)