The term "Big Three" is a simple one.
In sports, it refers to a trio of superstar players who all play for the same team. Whether you love them or hate them, you've certainly heard of them if you've followed sports at all this past year because of LeBron's decision to join the Miami Heat.
Many people don't believe Chris Bosh should be counted in the equation,—most notably the recently retired Shaquille O'Neal—but there are still two of the NBA's top five players displaying their talents in South Beach.
Such situations simply don't happen in the NFL because of the effective salary cap and the fact that 22 players are needed to field a team. However, I do believe that each team has three players on both sides of the ball who are a step above the rest in terms of skill and value to the team.
I'll leave some spots up for suggestions, but of course you can debate my selections.
Sources: Rotoworld, ProFootballReference