Tom Petty Week, Pt. 2: There Ain't No Easy Way Out
Taken from Petty's first "solo" album, Full Moon Fever, I Won't Back Down was co-written by ELO's Jeff Lynne. Although the album is credited to Tom Petty (sans The Heartbreakers) all members of his band (and the complete Traveling Wilburys, except for Mr. Dylan) were involved in recording it. The video to this songs has Ringo Starr on drums, but he didn't play on the album.
Tom Petty, Mike Campbell and Benmont Trench would also back Johnny Cash on his version of the song on American III: Solitary Man.
If you happen to have another version of this song, feel free to send it in and I'll include it in this list.