Beren and Lúthien

Of all that Tolkien wrote, perhaps his own favorite story was the Tale of Beren and Lúthien. Scholars certainly view it as the foundational core of his development of Middle Earth.

From the Wikipedia article:

The Tale of Beren and Lúthien was regarded as the central part of his legendarium by Tolkien. The story and the characters reflect the love of Tolkien and his wife Edith. Particularly, the event when Edith danced for him in a glade with flowering hemlocks seems to have inspired his vision of the meeting of Beren and Lúthien. Also some sources indicate that Edith's family disapproved of Tolkien originally, due to his being a Catholic. On Tolkien's grave, J. R. R. Tolkien is referred to as Beren and Edith is referred to as Lúthien.

It's an amazing story, and a true pleasure to hear as an audiobook.

I really enjoyed listening to the Silmarillion as an audiobook, in part because someone else was pronouncing all those dreadful Elvish names.

At the moment I don't have the Silmarillion on my MP3 player, and am enjoying Pilgrim's Progress as my bedtime story. But I did keep the Tale of Beren and Lúthien on the MP3 story, and will surely want to listen to it again before I want to revisit all of the Silmarillion.