A. W. Tozer: The first sermon I listened to (just yesterday) was "What Is It to Accept Jesus." Go to this link, look up that title, and click on "download."
D. Martyn Lloyd-Jones. I'd recommend a couple of sermons, but apparently they don't keep a long archive. They only have maybe a dozen sermons up at a time.
I don't think either Lloyd-Jones or Tozer had a voice for radio, so you'll have to get past a thick Welsh accent on the one hand, and a backwaters Appalachian twang on the other. But the content is what grips me.