Paul Hornung of the Green Bay Packers wore number 5 in the first super bowl in 1967. I don't think he played in either game but Pittsburgh's backup quarterback for Super Bowls IX and X, Terry Hanratty, wore number 5.
Bart Starr did. He was quarterback for the Green Bay Packers and wore 16. He played as starting quarterback for Super Bowl I (against Kansas City Chiefs) and Super Bowl II (Against Los Angeles now Oakland Raiders)
Troy Polamalu wore number 43 in Super Bowl XL. He is the Steelers strong safety.
"Dandy" Don Meredith wore #17 and is a 3x Pro Bowl Quarterback for the Dallas Cowboys. He was a Pro-bowler in 1966, 1967 & 1968.
In Super Bowl XLV, kicker Shaun Suisham wore #6 for the Steelers.
Wide receiver Yancey Thigpen wore #82 in Super Bowl XXX for the Steelers.
Backup quarterback Cliff Stoudt wore the number during his career with Pittsburgh (1977-1983). Interestingly, Stoudt won two Super Bowl rings before he ever played a down for the Steelers.
No one. There was no number 28 on the Patriots roster for super Bowl XXXVI.
Joe Theismann, who was the winning quarterback of Super Bowl XVII with the Washington Redskins, wore No. 7. On January 30, 1983, Washington defeated the Miami Dolphins, 27-17.