Reggie White
I think you have to live in Wisconsin to fully understand what REGGIE WHITE meant to the Green Bay Packers. This was a franchise that couldn't attract any marquee free agents and was wallowed in 4-12 seasons for more than a decade. When Reggie White decided to sign with Green Bay it signified a change in the organizations direction. After White, the first African-American free agent to sign with the Packers came to Green Bay, it opened the door for other athletes to help transform the Packers from the joke they were into a perennial contender.

Aside from being arguably the best defensive end in NFL history, White was paramount in transforming the Green Bay Packers. He also was active in the community and, aside from his homophobic blasts in front of the Wisconsin State Legislature, was an outstanding person and I think that along with the fact that he was only 43 is why his death is such a big deal.