Each of these sermons has changed and shaped me in some way. Some of them I have listened to/watched multiple times. I list them in the order in which I first heard them.
Paul Washer “Shocking Youth Message” (I realize that isn’t the title of this message, but most people who have listened to this sermon know it by that name. It completely overturns false assurance of salvation.)
John Piper “The Sovereignty of God” (this sermon changed my thoughts on a key doctrine because of the sheer weight of Scripture supporting his position. I have listened to or read numerous sermons by Mr. Piper, and I recommend that you check out the Desiring God website with his audio sermons, which have often been transcribed.)
Voddie Baucham “Predestination and Election”
Voddie Baucham “Faithfulness that Honors God” (Daniel 6 exposition; very encouraging!)
Paris Reidhead “Ten Shekels and a Shirt”
Compilation (Ravenhill, Reidhead, Tozer, Campbell, etc.) “The Revival Hymn” (this is a blend of music and numerous sermons which I have listened to many, many times and which has often brought me to tears of conviction and a new love for Christ. You can find it on YouTube and its own website now, as well.)