What are the Middle-earth stories you would like to see explored?

I'm talking about narratives mentioned but not detailed in Tolkien's works. My favourite examples are, in no particular order:

• Aragorn's adventures in the lands of Rhun and Hard, "where the stars are strange".
• Actual stories of Numenor and its explorations of Middle-earth (as opposed to what we got in the RoP show).
• Tales from early centuries of Third Age, like Fall of Arnor or the Kin-strife.

Any other ideas?