Alfredo Aceves, RHP: Signed out of Mexico as a free agent in 2008.
Joba Chamberlain, RHP: Drafted by the Yankees in the supplemental first round in 2006 from the University of Nebraska.
Phil Coke, LHP: Drafted by the Yankees in the 26th round in 2002, out of San Joaquin Delta Community College.
Phil Hughes, RHP: Drafted by the Yankees in the first round of the 2004 draft, from high school in Santa Ana, California.
Andy Pettitte, LHP: Drafted by the Yankees in the 22nd round in 1991 out of high school in Texas, signed as a draft-and-follow from San Jacinto JC in '92. Went to Houston as a free agent in 2004 but re-signed by the Yankees for 2007.
Mariano Rivera, RHP: Signed by the Yankees as a free agent from Panama in 1990.
David Robertson, RHP: Drafted by the Yankees in the 17th round in 2006, from the University of Alabama.
C.C. Sabathia, LHP: Drafted by the Cleveland Indians in the first round of the 1998 draft, out of high school in Vallejo, California. Signed by the Yankees as a major league free agent for 2009.
Melky Cabrera, OF: Signed by the Yankees as a free agent from the Dominican Republic in 2001.
Robinson Cano, 2B: Signed by the Yankees as a free agent from the Dominican Republic in 2001.
Francisco Cervelli, C: Signed by the Yankees as a free agent out of Venezuela in 2004.
Brett Gardner, OF: Drafted by the Yankees in the third round in 2005, from the College of Charleston.
Jerry Hairston JR, INF: Drafted by the Baltimore Orioles in the 11th round in 1997, from Southern Illinois University. Acquired by the Yankees in a trade in July 2009.
Derek Jeter, SS: Drafted by the Yankees in the first round in 1992, out of high school in Kalamazoo, Michigan.
Hideki Matsui, OF: Signed by the Yankees as a free agent from Japan in 2002. I am counting him as a "major league free agent" on the list below, not as a Yankee farm system product, since he was already an established star in Japan.
Jorge Posada, C: Drafted by the Yankees in the 24th round in 1990, out of high school in Rio Piedras, Puerto Rico.
Alex Rodriguez, 3B: Drafted by the Seattle Mariners in the first round in 1993, out of high school in Miami, Florida. The Yankees acquired him in a trade with the Rangers in 2004.
Trades or Waivers: Gaudin, Marte, Guzman, Hairston, Molina, Rodriguez, Swisher.
Yankees Farm System Products: Aceves, Chamberlain, Coke, Hughes, Rivera, Robertson, Cabrera, Cano, Cervelli, Gardner, Jeter, Posada.
Major League Free Agents: Burnett, Pettitte, Sabathia, Damon, Matsui, Teixeira.
Drafted from North American high schools: Burnett (8th), Gaudin (34th), Hughes (1st), Sabathia (1st), Damon (1-S), Jeter (1st), Molina (14th), Posada (24th), Rodriguez (1st),
Drafted from junior colleges: Coke (26th), Pettitte (22nd).
Drafted from four-year colleges: Chamberlain (1-S), Robertson (17th), Gardner (3rd), Hairston (11th), Swisher (1st), Teixeira (1st).
Undrafted free agents from North America: none.
Latin Free Agents: Aceves, Marte, Rivera, Cabrera, Cano, Cervelli, Guzman,
Asian Free Agents: Matsui