There are seven recognized that I know of: AP, Football Writers Association of America (FWAA), American Football Coaches Association (used to be known as the Kodak team), Walter Camp Football Foundation (WFCC), Sporting News, ESPN and Sports Illustrated.
Football
The National Collegiate Athletic Association recognizes College Football All-America Teams selected by the Associated Press, American Football Coaches Association, Football Writers Association of America, Sporting News, and the Walter Camp Football Foundation (WCFF) to determine consensus All-American
Consensus All-American