Gorbag of Mordor
I recently contributed to an article on Tor.com written by Irene Gallo on which of Tolkien's stories illustrators found most interesting for subjects to illustrate.
This is of course, a little like asking if one prefers chocolate chip cookie dough, or baked chocolate chip cookies. But there is an interesting difference in the two that begins to rise to the surface when you begin to discuss it.
The Hobbit is told from the viewpoint of a charming and not altogether reliable narrator in Bilbo, and the Lord of the Rings feels like it is told from the viewpoint of several different poet-historians who are not as given to the same vagaries of imagination as Bilbo. Because of this I find that the Hobbit allows a little more creative expression, especially in regards to the monsters. (And I love monsters who are just a little human.)
But The Lord of the Rings changes that, and the monsters there, are indeed monsters with only rare instances of humanity. But the humans there are deeper, and there we find the issue flipped, where now we find humans, who are just a little bit monster. Especially as they deal with matters of sons dying, or addiction. This too makes for an interesting vantage point to work from. Donato in particular writes that he finds that there are more opportunities that reveal the compassion and humanity of the characters in the Lord of the Rings, and so it presents a greater source of inspiration for his work.
Its an interesting article with contributions from Howe, Nasmith, Donato, Bosma, Adolfsson, Hickman, Kaluta and Miller.