For all intents and purposes: Melbourne.
However, essentially, there WAS no AFL in 1955, as competitions were each run within their own individual states - on a state by state basis.
However, when this changed, the VFL (Victorian Football League) affectively became the AFL by creating or drawing a few extra interstate clubs in to form a national competition.
So, effectively, the answer to the original question is: Melbourne.
The Melbourne Football Club had a real heyday period in the VFL during the 1950's decade, in which they won 5 premierships during its last 6 years!!! The grand final lost was in 1958.
Since this extraordinary golden period, the club has won only one flag - in 1964.
Essendon won the 2000 AFL grand final over Melbourne.
Geelong won the 2007 grand final by 119 points
Hawthorn
hawthorn
western bulldogs have onley won one grand final in afl.
In 1960 the VFL/AFL Premiership was won by: Melbourne
Geelong won the 2009 AFL grand final. Geelong scored 80 points. St Kilda scored 68 points.
The Brisbane Lions beat the Collingwood Magpies in the 2002 Grand Final.
The Geelong Cats won agains St. Kilda.
West Coast Eagles
The Geelong Cats won against St. Kilda.
Richmond 16.20.116 defeated Carlton 12.14.86