I've read most of Tolkien's books, but i still have a lot more to read. Here follows the list of Tolkien's complete works in chronological order. The History of Middle-Earth was released by J.R.R. Tolkien's son, Christopher Tolkien, from the notes professor Tolkien left behind after his death in 1973. The ones I own, have the mark * after them.

Farmer Giles of Ham (1949)

The Lord of the Rings: *

The Fellowship of the Ring (1954)

The Two Towers (1954)

The Return of the King (1955)

The Road Goes Ever On: A Song Cycle (1967) * [Notebook published together with composer Donald Swann]

Tree and Leaf (1964) *

The Silmarillion (1977) *

Unfinished Tales of Nъmenor and Middle-Earth (1980) *

Mr. Bliss (1982)

The History of Middle-Earth [12 books] (1986-1996)

1. The Book of Lost Tales, Part 1 *
2. The Book of Lost Tales, Part 2 *
3. The Lays of Beleriand
4. The Shaping of Middle-Earth
5. The Lost Road: And Other Writings
6. The Return of the Shadow
7. The Treason of Isengard
8. The War of the Ring
9. Sauron Defeated
10. Morgoth's Ring
11. The War of the Jewels
12. The People's of Middle-Earth
13. Index *

The Homecoming of Beorthnoth (1991)

Finn and Hengest (1996) *

Sir Gawain and the Green Knights Pearl and Sir Orfeo (1996) *

The Monsters and the Critics (1997)

Letters from Father Christmas (1998)

Roverandom (1998) *

Other things

Maps:

There and Back Again: The Map of the Hobbit *

The Map of Tolkien's Middle-Earth

The Map of Tolkien's Beleriand