Some guys (and at least one gal) at Redeemer put together an excellent new Francis Schaeffer study/research site.
Check it out here: Francis Schaeffer Studies
The writings of Francis Schaeffer were instrumental in the two years between college and seminary for me (1993-95). I was basically reformed after leaving Moody (but not exactly because of Moody), but wasn't quite able to put together a cogent worldview.
I read Schaeffer's A Christian Manifesto and things started to come together for me. I next read How Shall we Then Live? followed by The Church at the End of the 20th Century. I was hooked. Over a two year period I read every Schaeffer book, pamphlet, or paper I could find. I actually chose Covenant Seminary based on their opening of a new "Francis Schaeffer Institute" at the seminary. Two of my Covenant professors, Jerram Barrs and David Calhoun, were personally mentored by Francis Schaeffer in the 70's.
Two of my favorite books by Schaeffer, the only ones I have read twice in their entirety or more, are True Spirituality and The Letters of Francis Schaeffer. Letters is a compilation of various pastoral correspondence between him and students, congregants, or people he was counseling. Francis Schaeffer signed many of his letters "In the Lamb, Francis Schaeffer". For that very reason I sign my letters "In the Lamb, Tony".
People ask me why I like Francis Schaeffer so much? Very simply, Schaeffer possessed a near perfect balance of philosopher/theologian/bible scholar/and pastor I have ever come across. Most other authors I have read fall in to one or two of those categories. Schaeffer qualifies as top notch in all four. I'm tempted to add that Schaeffer was a prophet in addition to these other roles. It's almost eery reading How Shall We Then Live?, which shows the rise of Western Civilization and forecasts it fall (written in 1976), and seeing how it has all come to pass. Also, he may well have had the sweetest chin beard in the history of churchmen.
Learn more about Francis Schaeffer by checking out the site when you have a chance. The guys are doing a great job under the leadership of Dan Guinn.