Many people don't consider kickers athletes, and they may be right. Even though they're not "athletes" per se, they are without a doubt a vital part of every NFL team.
Adam Vinatieri may not have the biggest foot of any kicker, and if you need a 55-yard field goal in the second quarter, he may not be your guy. But, if it's the fourth quarter, the game is on the line and all you need is a field goal to win or tie, he's definitely your guy.
There has never been a better big-game, clutch-situation kicker than Vinatieri. He had one of the most famous field goals in NFL history in the "Tuck Rule" game against the Raiders in the 2001 AFC Championship. He hit a 45-yarder in blizzard conditions to send the game to overtime. In overtime, he hit another field goal to win the game. In the Super Bowl, he hit a 48-yarder on the final play of the game to secure the upset and the Pats' first Super Bowl Title. Two years later, in the Super Bowl against the Panthers, Vinatieri hit a 41-yard field goal with four seconds left to once again win the game for the Patriots.
When he left the Patriots after the 2005 season, he had kicked a total of 18 game-winning field goals with less then a minute left.
Vinatieri holds the postseason records for most field goals (42), for consecutive games with 3+ field goals (four), for most career points (187), for most field goals in single postseason (14), for most field goals in the Super Bowl (seven), for most total points in a single postseason (49) and most field goals in a single postseason game (five).
Runner Up: Morten Andersen