LeRoy Butler says no player in the NFL should EVER wear Bart Starr's #15 again -- telling TMZ Sports it should be retired league-wide just like Jackie Robinson's #42 in the MLB!! "Bart Starr is the best quarterback all time!" the Green Bay legend says. "Packer history, the guy was phenomenal." Of…

Ex-NFL DB Nick Collins -- Aaron Rodgers' AND Brett Favre's former teammate in Green Bay -- says with one more ring ... Rodgers will be the best Packer QB to ever live. "If he wins the Super Bowl this year, you would have to say he's the greatest," the three-time Pro Bowl safety tells TMZ Sports.…