Liberty Lobby

Liberty Lobby was a right-wing U.S. group founded c. 1955 by Willis Carto, a neo-Nazi, and defunct as of 2001 due to a lawsuit brought against them by the Holocaust denial group, the Institute for Historical Review (also founded by Willis Carto). Liberty Lobby promoted "controversial issues" (namely, a highly anti-Semitic worldview which they framed as populist and anti-Zionist) which other conspiracist right wing groups such as the John Birch Society disavowed.

Despite their name and office near Capitol Hill in Washington, D.C. they did little, if any, actual lobbying. They possibly played a role in Lyndon LaRouche's abandonment of Marxism when Liberty Lobby began promoting LaRouche writings to their right-wing audience starting in 1976.

Report from Iron Mountain controversy
In 1990, they reprinted Leonard C. Lewin's 1967 political satire Report from Iron Mountain: On the Possibility and Desirability of Peace, written in the form of a government panel report detailing that war is necessary to maintain power, convinced it was an actual government report and that it was in public domain. Lewin successfully sued for copyright infringement in court, proving he was the book's author. This hasn't stopped the "true believers" who insist the book is real and Lewin was a patsy, posing as the book's author in order to discredit it.

The Weekly World News of the Right
Their biggest influence came about because of their weekly newspaper, The Spotlight, which ran from 1975-2001. The paper was a notable source of several fringe topics, including:

They also took a special interest in investigative reporting on political and corporate scandals involving Zionists.
 * New World Order and John F. Kennedy assassination conspiracy theories,
 * promotion of alternative health remedies, including colloidal silver, Laetrile, shark cartilage and chelation therapy,
 * anti-Semitic reporting on Middle East affairs,
 * favorable reporting on fringe presidential candidates ignored by the "controlled" media, such as David Duke and Lyndon LaRouche,
 * history pieces on World War II arguing that the Axis was really just a coalition against communism,
 * articles defending Scientology against its critics,
 * and reporting on the Bilderberg Group and the Trilateral Commission.

The talk radio show "Radio Free America" during the 1990s, hosted by Tom Valentine and heard over WWCR, was sponsored by The Spotlight.

American Free Press
The weekly American Free Press is a successor newspaper to The Spotlight, founded in 2001 by former staffers. It is a significant source of 9/11 conspiracy theories, and is cited as a source by the 9/11 conspiracy film Loose Change.

The one real service it actually did
In 1981, an investigative-journalism magazine published a series of articles on Liberty Lobby, portraying them to be the nutjobs they were, and throwing in some accusations of Nazism for good measure. Liberty Lobby sued them, and long story short it ended up in the Supreme Court and now  is the single most-cited case in American jurisprudence (as it sets out the standard for, and every single American federal court must recite the rule it states in every case where summary judgment is sought, i.e. every single civil lawsuit in federal court that isn't decided on a motion to dismiss).