Well, here's the thing guys. When I started looking at pulps, I too made the mistake ( ) to look at covers as the main attraction of the hobby ... then I met real pulpsters and got the "Oh, so you're a cover collector" snub. Having been on the PulpMags group for several years now, I've learned that pulp collecting is all about the stories inside. All this to say that there isn't a "list" of classic covers as we have in comics. Plus there are too many cool pulp covers out there
Yep, I collect Edgar Rice Burroughs stories mainly in Pulps. Just in case you don't know in cases like ERB or Robert Howard their stories were published in Pulps first, then collected later in Hardcover books so the pulps are in fact the "first" printing of their stories.
Most stories of ERB in pulps don't even have his story as the cover art. In fact most are pretty boring covers compared to Weird Tales and others.