President Obama will deliver his fourth -- and arguably most important -- State of the Union address before a joint session of Congress on Tuesday.

In looking ahead to Obama’s speech, it’s helpful to look back through history at some of the most memorable State of the Union addresses ever delivered. Some came ahead of monumental policy achievements or championed notable ideas, while others were delivered before major setbacks, and in one case, a resignation. Below, we take a closer look, in reverse chronological order. And as always, the comments section awaits your input on our choices, as well as what we may have overlooked.

(For the text of every State of the Union, check out the University of California at Santa Barbara's American Presidency Project, an extremely helpful resource to which we link numerous times below.)

* 2010: Supreme Court Justice Samuel Alito was spotted mouthing the words “not true” in response to Obama’s characterization of the high court’s “Citizens United” ruling. The moment received widespread coverage, an important reminder that unexpected events in modern day State of the Union speeches can go viral in an instant, and people are taking notice of more than the speech itself.

* 2002: George W. Bush’s “axis of evil” remark that tied together Iraq, Iran and North Korea is arguably the most memorable line in all of his State of the Union speeches. In the speech, delivered just months after the Sept. 11, 2001 terrorist attacks, Bush warned that “by seeking weapons of mass destruction, these regimes pose a grave and growing danger.” The line would come back the haunt the Republican after the controversial invasion of Iraq did not lead to the discovery of such weapons.

* 1996: Bill Clinton’s declaration that the “era of big government is over” signaled his tack to the middle ahead of his reelection campaign that November. The speech illustrates the significance of reelection year State of the Union addresses, which tend to signal the boarder themes the president will underscore on the campaign trail later that year.

* 1975: Gerald Ford strikingly declared, “The state of the union is not good” in a speech he delivered only months after taking over for Richard Nixon, who resigned amid the Watergate scandal. Ford assumed the office of the presidency during a tough time for the country, and roughly two years later, voters opted for a different direction when they elected Democrat Jimmy Carter.

* 1974: Speaking of Nixon, just a year prior, in his final State of the Union address, the California Republican called for an end to the Watergate investigations. “One year of Watergate is enough,” declared Nixon. He would resign over the scandal just seven months later.

* 1964: Lyndon Johnson’s declaration of “unconditional war on poverty” in his first State of the Union address set the stage for programs like Medicare and Medicaid, work study and food stamps.

* 1941: Franklin Delano Roosevelt's famous "four freedoms" speech underscored the importance in the world of the freedom of speech and worship as well as the freedom from want and fear.

* 1862: Abraham Lincoln referred to the “fiery trial” of the Civil War in his State of the Union, which he delivered shortly after announcing the Emancipation Proclamation. The end of Lincoln’s State of the Union is particularly memorable: “ In giving freedom to the slave we assure freedom to the free -- honorable alike in what we give and what we preserve. We shall nobly save or meanly lose the last best hope of earth. Other means may succeed; this could not fail. The way is plain, peaceful, generous, just -- a way which if followed the world will forever applaud and God must forever bless.”

Lincoln delivered this address back on the days when presidents delivered written items to Congress on the state of the union. You can take a look at the end of Lincoln’s handwritten address at the National Archives Web site.

President Abraham Lincoln. (AP Photo/File)

* 1823: In warning Europeans countries against meddling with or colonizing areas in the Western Hemisphere, James Monroe espoused a firm position on U.S. foreign policy in his State of the Union, and one which would come to be known as the “Monroe Doctrine” and serve as a key pillar of U.S. foreign policy long after the Monroe presidency.

President James Monroe. (Gilbert Stuart / Library of Congress)

* 1790: This list would not be complete without the first State of the Union, which you can read in its entirety here. The issues before the nation in George Washington's time bear an eerie similarity to the current matters Obama is dealing with, as one report recently noted.

The nation's first president, George Washington. (National Portrait Gallery, Smithsonian Institution)