It is arsenal .F.C.
football is the most successful sport in the world
The Arkansas Razorbacks from the University of Arkansas are the most successful Arkansas football team. Arkansas does not have a National Football team, therefore the most successful team would be a college team.
Rangers Football Club are the most domestically successful football team in the world
because it is the capital of England and most of the football team are in London
The Manchester United club has the most support in London.
Brazil is the most successful Nation in the history of Football, having won the world cup 5 Times