The Hobbit and Watership Down were my favourite books as a boy. In some ways they're pretty similar books. I've read The Hobbit about 13 times, once in French. Although it's more child-oriented, I still think it's better than Lord of the Rings.
Actually, I was just thinking last night how I didn't think JRR Tolkien's decision to make the Bilbo's ring the McGuffin of LoTR was the best. For starters, how does this ring of power actually work? Does it just make you invisible or does it do something else. Does it make you lucky in war, or better at killing or more charismatic? I mean, if you're a king, a prince or mighty warrior and you suddenly disappear during the middle of a battle, surely that would have a disorienting effect on your followers. Perhaps it was just owning the ring that amplified your leadership qualities. But in that case, why did Gollum end up at the bottom of a mountain having to murder passing goblins to survive. Second point is, if the ring fits small hobbit fingers, how can it fit large warlord fingers? I'd have invented some other McGuffin for LoTR myself.
I couldn't make head or tail of The Silmarillion the first time I read it. The second time, I was struck by how much like The Old Testament it was, in particular Genesis. I never got through the Book of Lost Tales. One of my old line managers was pretty sure a lot of this stuff was actually written by JRR Tolkein's son.