Theologically the answer to this question is Jesus Christ.
Across the globe there are several Methodist Churches
(denominations). The United Methodist Church, the largest, has no
one person who is the leader of the church, like a Pope or
Archbishop. Instead, the form of governance is more like the US
federal government. It has Judiciary, a Legislative, and Executive
bodies. However, the Executive is composed of all the active
Bishops, not one President like in the U.S. Federal Government.
Official policy is set every four years at the General Conference,
a legislative body composed of representative delegates. Twice a
year a nine-person Judicial Council meets to interpret questions of
law brought before it (questions of policy and procedure, not of
censure or discipline). The Episcopacy (the Executive body) is
composed of all the active bishops. It does have a President, but
this bishop does not act as the president of the denomination, only
of the Council of Bishops.
In other churches, such as the Methodist Church of Great
Brittan, they do elect a President every year. The current (2009)
President of the Methodist Church of Great Brittan is The Reverend
David Gamble. You can read more about this here:
http://www.methodist.org.uk/index.cfm?fuseaction=opentogod.content&cmid=1567