The Calvin Johnson catch

This is the famous catch, which the referees called not a catch. This was the beginning of the "process of the catch" reasoning, saying that even if you have total control with knees down, you need to complete the process of the catch. Since this ruling, the NFL has struggled to make clear exactly what counts as a catch, and other players have struggled with calls going against them because of this.

Gallaraga's perfect game

This one may be the worst call I have ever seen in my lifetime. In the 9th inning with 2 outs, Armando Gallaraga had a perfect game going. On the last out, the batter hit the ball to the first baseman and Gallaraga ran over to first to cover the bag. Gallaraga caught the ball before the runner got there, however it was very close. The umpire called the runner safe and the perfect game was ruined. It was very clear in the replay that the runner was out, and if instant replay would have been in baseball at this point, Gallaraga would have a perfect game.

Picked up PI flag against Pettigrew

The Lions get very few playoff appearances, so when one gets spoiled by a no-call, it is very frustrating. Hitchens clearly interfered with Brandon Pettigrew, and the penalty and automatic first down would've given the Lions an opportunity to come back, as Matthew Stafford is famous for doing. A referee threw a flag, but then picked it up with no explanation. Later, the NFL admitted that it should've been a penalty.

Last play of Lions vs Seahawks on MNF

The Lions were driving down the field making a comeback against the Seahawks. Calvin Johnson fumbled at the 1-yard line, and then the ball drifted into the end zone, where a Seahawks player batted the ball out through the back of the end zone. This is not a popular play or well-known rule, but the rulebook does state that the Lions then should've received the ball at the 1 and would've put them in a fantastic position to score and win the game.

Facemask call against Aaron Rodgers

In the last seconds of the Lions vs Packers game, the Lions were winning, and all they had to do was not allow a Hail Mary. The refs called a controversial facemask against the Lions, which it appeared it could've been from a first glance, but as you slow it down and look at the replay, Taylor's thumb only grazed the facemask, and there was no grip, and therefore shouldn't have been called. Following the first down and 15-yard penalty, on the next play, Rodgers threw a game-winning Hail Mary as time expired.