I would have to say Micheal Jordan.
Utah is not popular in sports... John Stockton.
Steve Prefontaine
Troy Aikman
Michael Vick
Brett Favre
Darryl Sittler
Perhaps the best known Iowan in sports history was Bob Feller.
georges st. Pierre
John Madden does he count?
Brian Urlacher
Back in the day: Hakeem Olajuwon.
Chase Utley (2nd baseman)