The thread title is "Dropped Passes" not "Drops by Receivers" so how about one by a defensive back?
The dropped (easy) interception by Lewis Billups in Super Bowl XXIII was a game-changer and perhaps a team-of-the-decade-changer, too. The 49ers scored on the next play and went on to win their third title under Bill Walsh. And, as they say, "the rest is history."
But had Billups held on to that "gimme" interception things might have been very different...