Honorable Mentions (in no particular order)
Emmanuel Sanders
When Sanders came to Denver in 2014, the team was removed from their first Super Bowl appearance since the late 1990s. And it was a nightmare. Denver needed help on defense. But perhaps the biggest underrated impact was signing Sanders.
With Eric Decker left in free agency, the Broncos needed a second wide out to help them out. Sanders filled that role and more. He would record over 5,000 receiving yards in his five and half seasons in Denver.
He would help the Broncos win Super Bowl 50 with some of his key receptions.
Brian Dawkins
In what was a dark time around the time he arrived in Denver in 2009, Brian Dawkins was one of the bright spots on the team as a leader. He played for the entire Josh McDaniels era. Hence the dark times. A true leader on the defense before his retirement, Dawkins was a player that you can get really excited to watch.
Perhaps one of my favorite moments of his was his epic Monday Night Football speech in 2009 after the Broncos suffered their first lost against the Ravens. While it did not do a lot in a loss, it truly showed me how passionate he is about the game.
Alfred Williams
While his NFL career was not very long, he made the most impact during his time with the Denver Broncos. He arrived in 1996 and provided some big moments defensively for the Broncos. In just his first season, he was named All-Pro.
Neil Smith
When I found out (I was young and did not have any knowledge) that Neil Smith switched from Kansas City to Denver, I gave him my ultimate applause. As a nose tackle, Smith made some big time moves as he was looking for his first championship. Despite only being in Denver for a short time, he did quite a bit in Denver to help the team get their first two titles.
Mark Schlereth
Before the offensive line began making such a huge impact, Schlereth was one of the few right guards that made a huge impact on the game. His ability to protect John Elway was what led the team to their two Super Bowls.