NFL Connections #85, Answers
The full solution: all four groups and the 16 names, sorted from the easiest group to the trickiest.
2000s star QBs
Peyton Manning, Tom Brady, Donovan McNabb, Brett Favre
2000s star running backs
LaDainian Tomlinson, Shaun Alexander, Edgerrin James, Tiki Barber
2000s star receivers
Randy Moss, Terrell Owens, Marvin Harrison, Chad Johnson
2000s star defenders
Ray Lewis, Ed Reed, Julius Peppers, Champ Bailey