1824 - John Quincy Adams won the election despite not winning the popular vote. This is due to the fact that there were four candidates running and as a result, no one person was able to get a simple majority of the electoral college to win. Here's the rundown:

Adams Popular vote: 113,122 Percentage: 30.9% Electoral College: 84

Jackson Popular vote: 151,271 Percentage: 41.4% Electoral College: 99

Clay Popular vote: 47,531 Percentage: 13.0% Electoral College: 37

Crawford Popular vote: 40,856 Percentage: 11.2% Electoral College: 41

131 electoral votes were needed and since no one got enough, this issue went to the House of Representatives. Adams was picked and oddly enough, Clay, who was Speaker of the House, was picked as Secretary of State. Sounds like a "Corrupt Bargain".

1876 - Rutherford B Hayes lost the popular vote to Samuel Tilden but won the election.

Hayes Popular vote: 4,034,311 Percentage: 47.9% Electoral College: 185

Tilden Popular vote: 4,288,546 Percentage: 50.9% Electoral College: 184

185 electoral votes were needed to win however some of the states races were too close to call. Instead of contesting, the Democrats agreed for Hays to be president in exchange for the end of Reconstruction and for all Federal Troops to withdraw from the south. This compromise basically doomed the south and allowed for black codes and Jim Crow laws from undoing all the progress that was accomplished during Reconstruction and in the Grant Administration.

1888 - Cleveland, despite winning the popular vote, lost reelection to Benjamin Harrison.

Cleveland Popular vote: 5,534,488 Percentage: 48.6% Electoral College: 168

Harrison Popular vote: 5,443,892 Percentage: 47.8% Electoral College: 233

201 electoral votes were needed and despite loosing the popular vote, Harrison won, however he would end up loosing to Cleveland in 1892 when the rematched. This is why Cleveland is the only president to serve two non consecutive terms.