Busts come in all shapes and sizes and may vary ever-so-slightly based on your scoring system, but the players mentioned below would be considered a bust no matter how you slice it. Now, I am not citing players whose years were cut short by injury, such as Doug Martin, since you cannot predict injuries to normally healthy players. Drafting one of these players cannot be the sole reason for you not making the playoffs, but it surely didn't help your efforts.
QB: Matt Ryan (ATL) - sure, Matty Ice's season was indirectly impacted by an unexpected injury to Julio Jones and a slow recovery by Roddy White, but, with no running game and with plenty of passing opportunities, he should have turned out better numbers. He broke 15 points in just half of his games this season. With an ADP in the 3rd/4th round, you could have had a nice WR at that pick and picked up a much more productive Philip Rivers, or even Big Ben or Big Red, many rounds later.
RB: Ray Rice (BAL) - After 4 straight injury-free years of high volume production, I guess it was inevitable that Rice would slow down, but he came to an abrupt stop this season. He had only 4 games of double-digit points, one 100-yard game (against the league's worst rush defense) and a meager 3 games with TDs. It is hard to predict how far his ranking will fall next year, but another year like this will seen him fade out with Tony Richardson.
WR: Victor Cruz (NYG) - If you traded Cruz after his sizzling first quarter of the season (over 400 yards and 4 TDs), you were giddy after watching Cruz put up one 100-yard game, zero TDs and less than 600 yards over the remainder of the season on someone else's team. If he was on your team, how long did you wait before benching him? My guess is that it was too long. Everyone knows that Eli Manning has been the most over-rated player to ever step on the field, but Cruz has been able to turn his wobbly 5-yard passes into long TDs since he first stepped onto the field. Not this season though.
TE: Tyler Eifert (CIN) - Blame this one on the hype and for buying into a rookie tight end. Eifert was a stud at Notre Dame and we all assumed that it would translate straight into the professional ranks. Unfortunately, OC Jay Gruden could not find a way to effectively utilize Eifert's talents. I believe that the success of Giovani Bernard also had an impact on Eifert's season as Bernard has 56 catches out of the backfield.
