Well, I have no kids of my own yet, but should I decide to have kids, I would absolutely read out loud to them, and Tolkien would certainly make the list. When I was a toddler, my mother became ill for an extended period of time and wasn't up to doing anything active with me, so she would spend hours upon hours just reading to me. I have vivid memories of sitting in her lap as she read the
Little House and
Narnia books to me and asking her to point to the words. I learned to read at a very young age, and I have always been an avid reader, and I think both are simply a result of having someone spend so much time reading aloud to me. That is something I would absolutely want to pass on to my kids.
I first read
The Hobbit when I was in third grade and someone in school loaned it to me. I absolutely loved it from that very first read, and I remember I was left with so many questions that my mother handed me a copy of
The Fellowship of the Ring like the day after I finished
The Hobbit. (probably just to shut me up...

) LOTR was the first set of books that I ever wore out.

As far as reading "big" or "grown up" books to kids, again, I am not a parent, but I am a teacher, and I think it's great to push kids in a positive way like that. When kids find something that interests them, they will push themselves to explore it or figure it out if they have the encouragement and positive support to do so. Like HP, I think
The Hobbit and LOTR are engaging stories that can grip kids (and adults for that matter) and draw them in, and make them want to find out what happens, even if there are some hard words along the way.