Let me just list a bunch of books I read and loved
Redwall Series, I loved them when I was a kid. Just read them over and over like a little imbecile.
LotR. All of everything, including The Hobbit.
Bartimaeus Trilogy. Great humor, great plot, just excellent overall.
Artemis Fowl. Same general reasons that I loved Bartimaeus books, but the characters were more fun to me (not to dis Bartimaeus or Ptolemy.)
Godel Escher Bach: an Eternal Golden Braid. Brain food, loved it.
The Way Things Work. Another old-time favorite.
I liked some of the Narnia books but others just bored me.
Eragon Series. A good read overall, but mainly for the epic plot; I wasn't particularly struck by it as being good writing.
I read some of the Pern series because my sister had it and I needed something to read, and I did like some of it. However, it's kinda just an epitome of a genre.
Ender's Game is an excellent, excellent book and I recommend it for anyone.
The Discworld Series. High humor and fun plot. What more could I ask for?
Foucault's Pendulum. Read it a while back and was immersed by it. The detail was so exquisite that you had to be careful not to get lost and forget the current situation. I still didn't get as much out of it as I could have because I was trying to read for both the detail and the overall plot and thus skimped on both.
Young Merlin Series was quite a good read for me; kind of classical fantasy.
I'll probably think of some others and come back to this list.