Broyles was on pace to win it (2011) I believe but his late season injury cost him down the stretch. Lil Poke had Justin Blackmon won the previous season and was Broyles only competition but Ryan appeared to be the favorite.
Shepard was great but never had the stats or, more importantly, the hype to win the award. He's getting the last laugh.
Clayton had a brilliant 2003 campaign but a certain fellar named Larry Fitzgerald was in the way. Many argue that he deserved the Heisman over Jason White.