Back-to-Back Titles in Major League Sports

Note: Those are pieces of confetti in that picture, not Band-Aids on anyone's faces.

Baseball
1872-75 Boston Red Stockings (4 straight, forerunners of Atlanta Braves)
1877-78 Boston Red Stockings
1880-82 Chicago White Stockings (3 straight, forerunners of Chicago Cubs)
1885-86 St. Louis Browns (forerunners of Cardinals)
1888-89 New York Giants (now in San Francisco)
1891-93 Boston Beaneaters (3 straight, forerunners of Atlanta Braves)
1894-96 Baltimore Orioles (3 straight, defunct, no connection to the current team with the name)
1897-98 Boston Beaneaters
1899-1900 Brooklyn Superbas (forerunners of Los Angeles Dodgers)
1901-02 Pittsburgh Pirates
1903-04 Boston Pilgrims (soon to be Red Sox)
1907-08 Chicago Cubs
1910-11 Philadelphia Athletics (now in Oakland)
1915-16 Boston Red Sox
1921-22 New York Giants
1927-28 New York Yankees
1929-30 Philadelphia Athletics
1936-39 New York Yankees (4 straight)
1949-53 New York Yankees (5 straight)
1961-62 New York Yankees
1972-74 Oakland Athletics (3 straight)
1975-76 Cincinnati Reds
1977-78 New York Yankees
1992-93 Toronto Blue Jays
1998-2000 New York Yankees (3 straight)

Football
1922-24 Canton Bulldogs (3 straight, defunct)
1929-31 Green Bay Packers (3 straight)
1932-33 Chicago Bears
1940-41 Chicago Bears
1948-49 Philadelphia Eagles
1952-53 Detroit Lions
1954-55 Cleveland Browns
1958-59 Baltimore Colts (now in Indianapolis)
1960-61 Houston Oilers (AFL, forerunners of Tennessee Titans)
1961-62 Green Bay Packers
1964-65 Buffalo Bills (AFL)
1965-67 Green Bay Packers (3 straight)
1972-73 Miami Dolphins
1974-75 Pittsburgh Steelers
1978-79 Pittsburgh Steelers
1988-89 San Francisco 49ers
1992-93 Dallas Cowboys
1997-98 Denver Broncos
2003-04 New England Patriots

Basketball
1949-50 Minneapolis Lakers (now in Los Angeles)
1952-54 Minneapolis Lakers (3 straight)
1959-66 Boston Celtics (8 straight)
1968-69 Boston Celtics
1987-88 Los Angeles Lakers
1989-90 Detroit Pistons
1991-93 Chicago Bulls (3 straight)
1994-95 Houston Rockets
1996-98 Chicago Bulls (3 straight)
2000-02 Los Angeles Lakers (3 straight)
2009-10 Los Angeles Lakers
2012-13 Miami Heat (accomplished last night)

Hockey
1893-94 Montreal Hockey Club (sometimes listed as "Montreal AAA")
1897-98 Montreal Victorias
1899-1900 Montreal Shamrocks
1901-02 Winnipeg Victorias
1903-05 Ottawa Hockey Club (3 straight, forerunners of original Ottawa Senators, defunct)
1906-08 Montreal Wanderers (3 straight)
1912-13 Quebec Bulldogs
1920-21 Ottawa Senators
1930-31 Montreal Canadiens
1936-37 Detroit Red Wings
1947-49 Toronto Maple Leafs (3 straight)
1954-55 Detroit Red Wings
1956-60 Montreal Canadiens (5 straight)
1962-64 Toronto Maple Leafs (3 straight)
1965-66 Montreal Canadiens
1966-68 Montreal Canadiens
1974-75 Philadelphia Flyers
1976-79 Montreal Canadiens (4 straight)
1980-83 New York Islanders (4 straight)
1984-85 Edmonton Oilers
1987-88 Edmonton Oilers
1991-92 Pittsburgh Penguins
1997-98 Detroit Red Wings

*

3 Straight
1872-75 Boston Red Stockings (4)
1880-82 Chicago White Stockings
1891-93 Boston Beaneaters
1894-96 Baltimore Orioles
1903-05 Ottawa Hockey Club
1906-08 Montreal Wanderers
1922-24 Canton Bulldogs
1929-31 Green Bay Packers
1936-39 New York Yankees (4)
1947-49 Toronto Maple Leafs
1949-53 New York Yankees (5)
1952-54 Minneapolis Lakers
1956-60 Montreal Canadiens (5)
1959-66 Boston Celtics (8)
1962-64 Toronto Maple Leafs
1965-67 Green Bay Packers
1972-74 Oakland Athletics
1976-79 Montreal Canadiens (4)
1980-83 New York Islanders (4)
1991-93 Chicago Bulls
1996-98 Chicago Bulls
1998-2000 New York Yankees
2000-02 Los Angeles Lakers

4 Straight
1872-75 Boston Red Stockings
1936-39 New York Yankees
1949-53 New York Yankees (5)
1956-60 Montreal Canadiens (5)
1959-66 Boston Celtics (8)
1976-79 Montreal Canadiens
1980-83 New York Islander

5 Straight
1949-53 New York Yankees
1956-60 Montreal Canadiens
1959-66 Boston Celtics (8)

6, 7 or 8 Straight
1959-66 Boston Celtics