sentences:  The most successful season of "Australian Idol" was the first one in 2003, with the contestants achieving 18 of the 34 "Australian Idol" number ones, and almost half the certifications.Season one winner Guy Sebastian has been the most commercially successful "Australian Idol" contestant, with season four runner up Jessica Mauboy second.They are followed by season one runner up Shannon Noll, season five runner up Matt Corby, season two runner up Anthony Callea, and season four winner Damien Leith.