Some who won a Super Bowl after leaving the Bills... (source http://www.completesuperbowl.com)
Tom Flores - SB IV KC Chiefs, Coach for Raiders in SB XV, XVIII
Remi Prudhomme - SB IV KC Chiefs
Marlin Briscoe - SB VII, VIII Miami
Jim Dunaway - SB VII Miami
Mike Kindig - SB VII Miami
Bob Chandler - SB XV Raiders
Keith Moody - SB XV Raiders
Bob Nelson - SB XV, XVIII Raiders
Sam Wyche - QB Coach for 49ers in SB XVI
Mario Clark - SB XIX 49ers
Dale Hellestrae - SB XXVII, XXVIII,XXX Cowboys
Don Beebe - SB XXXI Packers
Mike Lodish - SB XXXII, XXXIII Broncos
Justin Armour - SB XXXIII Broncos
Rick Tuten - SB XXXIV Rams (injured - didn't play)
Sam Gash - SB XXXV Ravens
Matt Stevens - SB XXXVI Patriots*
Antowain Smith - SB XXXVI, XXXVIII Patriots*
Rob Johnson - SB XXXVII Bucs
Larry Centers - SB XXXVIII Patriots*
Ted Washington - SB XXXVIII Patriots*
Pete Metzelaars - Offensive QC Coach SB XLI Colts
Kevin Gilbride - OC SB XLII Giants
Dick LeBeau - DC SB XLIII Steelers
Jabari Greer - SB XLIV Saints
Anthony Hargrove - SB XLIV Saints
Pierson Prioleau - SB XLIV Saints
Gregg Williams - DC SB XLIV Saints