According to the Wikipedia
http://en.wikipedia.org/wiki/Nontrinitarian
Nontrinitarian groups
Monarchianism
Arianism
Socinianism
Deism
Unitarian Christians
American Unitarian Conference
The Church of Jesus Christ of Latter-day Saints (LDS Church; see also Mormon)
Living Church of God
Unitarian Universalist Christian Fellowship*
Magi Network*
Church of Christ, Scientist
Oneness Pentecostals
Jehovah's Witnesses
Unification Church
Christadelphians
Church of God General Conference (Abrahamic Faith)
Polish Brethren
Doukhobors
Molokan
The Way International
Gospel Assembly Church
* Independent affiliates of the Unitarian Universalist Association
Other groups which reject the Trinity doctrine
Iglesia ni Cristo
True Jesus Church
Nontrinitarian people
Natalius[1], ~200
Paul of Samosata, 269
Arius, 336
Constantius II, Byzantine Emperor, 361
Antipope Felix II, 365
Aëtius, 367
Ulfilas, Apostle to the Goths, 383
Muhammad, 632, see also Isa
Ludwig Haetzer, 1529
Michael Servetus, 1553, burned at the stake in Geneva under John Calvin
Ferenc Dávid, 1579
Fausto Paolo Sozzini, 1604
John Biddle, 1662
John Locke, 1704
Isaac Newton, 1727
William Whiston, 1752
Jonathan Mayhew, 1766
Benjamin Franklin, 1790
Joseph Priestley, 1804
Joseph Smith, 1805
Thomas Paine, 1809
Thomas Jefferson, 1826
James Madison, 1836
William Ellery Channing, 1842
Robert Hibbert, 1849
Ralph Waldo Emerson, 1882
James Martineau, 1900
Charles Taze Russell, 1916
Neville Chamberlain, 1940
William Branham, 1965
Herbert W. Armstrong, 1986