Since 1977, Collegiate Baseball Magazine has been crowning a national champion in high school baseball. The only school to win the title twice is Bishop Amat in La Puente CA, who won back to back in 2001 and 2002. Check out the full list of high school baseball national champions below.

1977: Redwood HS, Larkspur, CA (33-4)
1978: Southeast HS, Wichita, KS (23-0)
1979: White Oak HS, NC (22-0)
1980: Bullard HS, Fresno, CA (28-2)
1981: Bowie HS, MD (22-0)
1982: Madison Central, Richmond, KY (40-0)
1983: Northwest HS, Omaha, NE (21-1)
1984: Tate HS, Pensacola, FL (38-1)
1985: Miami Lakes HS, Hialeah, FL (32-1),Oak Forest HS, IL (36-1)
1986: Esperanza HS, Anaheim, CA (25-3-1)
1987: LaPorte HS, IN (34-2) , Cooper HS, Abilene, TX (33-3)
1988: Memorial HS, West New York, NJ (28-1)
1989: Sarasota HS, FL (32-1)
1990: Carlsbad HS, NM (32-1)
1991: Northeast HS, Pasadena, MD (24-0)
1992: Cherry Hill West HS, NJ (27-3)
1993: Arundel HS, MD (21-1)
1994: Start HS, Toledo, OH (31-0)
1995: Germantown HS, TN (38-0)
1996: Westminster Christian, Miami, FL (36-0-1)
1997: George Washington, New York, NY (44-2)
1998: Edwardsville HS, IL (40-4)
1999: Lassiter HS, Marietta, GA (35-2)
2000: Gloucester Catholic, Gloucester City, NJ (33-1)
2001: Bishop Amat, La Puente, CA (27-2)
2002: Bishop Amat, La Puente, CA (28-2)
2003: Chatsworth HS, CA (33-1)
2004: La Cueva HS, Albuquerque, NM (28-0)
2005: Russell County, Seale, AL (38-1)
2006: The Woodlands, TX (36-1)
2007: Seton Hall Prep, West Orange, NJ (32-1)
2008: Don Bosco Prep, Ramsey, NJ (30-0)
2009: Menchville, Newport News, VA (26-2)
2010: Sumrall HS, MS (35-1)
2011: Broken Arrow HS, OK (36-2)
2012: Bishop Gorman, Las Vegas, NV (39-3)
2013: Pensacola Catholic, Pensacola, FL (30-0)
Recently more organizations have gotten into the high school baseball ratings game. Here are the various 2013 National Champions by ranking authority:

USAToday Sports Super 25: Pensacola Catholic, Pensacola, FL. (30-0)
MaxPreps Xcellent 50: Pensacola Catholic, Pensacola, FL. (30-0)
Freeman Computer Rankings: Harvard-Westlake, Studio City, CA (28-4)