Seriously though, Collingwood Football Club - has lost 25 Grand Finals in 110 years of AFL history, I'm not just doing this to wind up Matt, although that's the main reason itbt, but they're not called the Collywobbles without good reason.
GFs lost:
1901
1905
1911
1915
1918
1920
1922
1925
1926
1937
1938
1939
1952
1955
1956
1960
1964
1966
1970
1977
1979
1980
1981
2002
2003