National History Day (NHD) developed a terrific interactive website featuring 100 leaders from Ashoka to Ronald Reagan.
You can filter the leaders by time period, country, and type (political, economic, military, religious, etc). Clicking on a leader gives you a flashcard with a picture and basic biographical information, along with a summary and a short bulleted list about the leader's significance.
National History Day teachers also created some lesson plans for both middle and high school students. One plan calls for students to create a "fakebook" page for one of the leaders that might be a unit you are studying.
My thanks to Liz Ramos for tweeting the link.