Maxwell Lord

The greatest trick the devil ever pulled was convincing the world he doesn't exist.

Initially, Lord worked behind the scenes to establish the League, while under the control of a villainous computer created by Metron (a later retcon would say that this was actually the villainous computer program Kilgore, which had taken over Metron's machine). The computer wanted Max to set up a worldwide peacekeeping organization, as part of its plan to dominate the world.
Lord's ruthlessness at this time was illustrated when he set up a disturbed would-be terrorist as a villain for the League to defeat, resulting in the man's death. (The would-be terrorist believed he had a bomb connected to his heartbeat, but in fact, Max had disconnected it.) Later, however, he rebelled against the computer and (seemingly) destroyed it.

Once free of the computer's influence, Lord was portrayed as an amoral businessman, but not a real villain.

More on this character soon, for the mean time read the character's bio here:
http://dc.wikia.com/wiki/Maxwell_Lord_IV_(New_Earth)