It depends on what denomination you are in. There are many different names. Preachers, pastors, priests..
Pastor
There is no local leader. The minister has less "power" than the elders of the church do. Each church is indepent from one another. The preacher can be called by his name or more formally as Mr.
William Mompesson.
Marty Sampson's name listed on his biography is Martin W. Sampson. He is the leader of the church, Hillsong Church, in Australia.
The name of the leader of the Catholic Church, whether in Europe or anywhere else is Our Blessed Lord, Jesus Christ. His Vicar on earth is the Pope in Rome, currently Pope Benedict XVI.
The leader of the Church of Christ is called Reverend and President of the Church.
Jesus Christ is the invisible leader of the Church.
God is the leader of worship ina church
Currently it is Archbishop Seán Brady.
The Protestant Church has no one leader. Each denomination within the Protestant Church has it's own leader.
Members of the Church of Jesus Christ of Latter-day Saints (the "Mormon" church) believe that Jesus Christ is the leader of the church and that He leads the church through direct revelation to a modern prophet. The current prophet (Feb 2011) is Thomas S. Monson.
the leader of the Byzantine Church was called the Metropolitans.