Christianity Today has published a list of the top 50 books that have shaped evangelical thought as it actually exists now. Here's the list; the one's I've read are bolded.
50.Revivalism and Social Reform. Timothy L. Smith
49.Knowledge of the Holy. A. W. Tozer
48.The Hiding Place. Corrie ten Boom with John and Elizabeth Sherrill
47.The New Testament Documents: Are They Reliable? F. F. Bruce
46.Out of the Saltshaker and into the World. Rebecca Manley Pippert
45.The Scandal of the Evangelical Mind. Mark A. Noll
44.The Gospel of the Kingdom. George Eldon Ladd
43.Operation World. Patrick Johnstone
42.The Purpose-Driven Life. Rick Warren
41.Born Again. Charles W. Colson
40.Darwin on Trial. Phillip E. Johnson
39.Desiring God. John Piper
38.The Gospel in a Pluralist Society. Lesslie Newbigin
37.God's Smuggler. Brother Andrew with John and Elizabeth Sherrill
36.Left Behind. Tim LaHaye and Jerry B. Jenkins
35.The Stork Is Dead. Charlie W. Shedd
34.This Present Darkness. Frank E. Peretti
33.The Late Great Planet Earth. Hal Lindsey with C. C. Carlson
32.The Cross and the Switchblade. David Wilkerson with John and Elizabeth Sherrill
31.The Next Christendom. Philip Jenkins
30.Roaring Lambs. Robert Briner
29.Dare to Discipline. James Dobson
28.The Act of Marriage. Tim and Beverly LaHaye
27.Christy. Catherine Marshall
26.Know Why You Believe. Paul E. Little
25.Boundaries. Henry Cloud and John Townsend
24.The Meaning of Persons. Paul Tournier
23.All We're Meant to Be. Letha Dawson Scanzoni and Nancy A. Hardesty
22.The Genesis Flood. Henry M. Morris and John C. Whitcomb
21.The Master Plan of Evangelism. Robert Emerson Coleman
20.A Wrinkle In Time. Madeleine L'Engle
19.The Cost of Discipleship. Dietrich Bonhoeffer
18.The Divine Conspiracy. Dallas Willard
17.What's So Amazing About Grace? Philip Yancey
16.Basic Christianity. John Stott
15.The Uneasy Conscience of Modern Fundamentalism. F. H. Henry
14.Let Justice Roll Down. John M. Perkins
13.Evidence That Demands a Verdict. Josh McDowell
12.Power Evangelism. John Wimber with Kevin Springer
11.Celebration of Discipline. Richard J. Foster
10.Evangelism Explosion. D. James Kennedy
9.Through Gates of Splendor. Elisabeth Elliot
8.Managing Your Time. Ted W. Engstrom
7.Rich Christians in an Age of Hunger. Ronald J. Sider
6.The Living Bible. Kenneth N. Taylor
5.Knowing God. J. I. Packer
4.The God Who Is There. Francis A. Schaeffer
3.Mere Christianity. C. S. Lewis
2.Understanding Church Growth. Donald Anderson McGavran
1.Prayer: Conversing With God. Rosalind Rinker
It's a mark of the accuracy of the list that, despite not having read most of the works here, I have heard of most of them, and come across most of them indirectly (allusions, quotations, excerpts, summaries etc.). As Lee notes, they are of very uneven quality. I highly recommend both The Hiding Place and Christy, though. The Hiding Place is Corrie ten Boom's account of her family's hiding of Jews and underground resistance fighters in Nazi-occupied Holland. The Ten Booms were imprisoned and a number of them died there; Corrie herself, although relatively young, spent ten months in prison, finally ending up in the Ravensbrook concentration camp. Christy is a novel about a young rich girl who sets out to teach a Mission School in the poorest part of the Appalachians; when there she struggles with problems like illiteracy, but also finds that the poor she's teaching have as much to teach her as she does them.