I've had people people ask me for recommendations of what to read if they like Tolkien, expecting me to name contemporary fantasy authors. And that's fine, obviously more or less all modern fantasy has been inspired by Tolkien, in many cases directly ripping it off, and there's plenty to enjoy in that style of fiction. That said, The Silmarillion in particular always leads me to recommend religious and mythological texts, ancient epics and sagas, and that sort of thing over pretty much any post-Tolkien fantasy authors.

Interested in Tolkien? Read Beowulf, the Morte d'Arthur, the Books of Genesis and Exodus, Sir Gawain and the Green Knight, the Icelandic Sagas, the Kalevala, the Iliad and Odyssey, the Theogony, the Tain Bo Cuailnge, the Mabinogion. Tolkien wanted to create a mythology for England, so if you want to understand his motivations and influences that's where you should turn.