I’ve tried to read The Colour of Magic several times, always give it up as a bad job. Just can’t get into it, or anything else Pratchett wrote.
The list is missing Narnia and Gormenghast.
There are also some fantasy series that should be noted - the Recluce books by L.E. Modesitt Jr., the Mithgar books by Dennis McKiernan, and the Elantra series by Michelle Sagara. All are multi-novel series with some books better than others. In particular, don’t be put off by the first trilogy in McKiernan’s Mithgar series - The Iron Tower. It was originally written as Tolkien fan fiction, and it reads like it. He fleshed his world out in later books, though, turning it into Tolkienian fantasy that is nothing like Tolkien. He and Michelle Sagara both explore what it would be like to be immortal, which I find interesting.
The first four books in the Disk World should actually be read after you have gotten to know the Disk World. Or maybe not at all. At the time he was just playing with the idea of a story that made fun of fantasy tropes. Later he started putting some thought into the world he was creating. The best place to start is with the book “Guards, Guards”, a tribute to all the poor slubs in fantasy books that exist only to be killed by the hero or serve as cannon (arrow?) fodder.
Narnia is seventh on the list.