For a brief period, J'onn J'onzz was the cover featured star of House of Mystery. Six of those covers garnered stories in this volume, and we only need four for the back of the dust jacket. Why don't you take your picks?
The Martian Manhunter Archives Vol.4 back cover web page, as explained by its creator:
For me, #143 is a lock, as it's the first Manhunter cover, and a swell Zook spotlight. Next, #145, my personal favorite of these issues. #146 just because it's a nice cover to an almost decent story, and close with #147, for the gonzo factor.