tough call
Rosy, I didn't see your avatar before today, it is beautiful!
I haven't read the HP books, so I cannot comment on them. But between CON and LOTR, it would be very difficult to call. As a child/teen, I would have said Narnia hands down (and I did read the ring cycle as a child/teen -- but preferred Narnia). Now, though, I see that as adult novels, LOTR has a complete history and mythology with language and dialect, that makes it the more intricate and involving of the two, for an adult. At the same time: as an adult whose life is sometimes scary and bewildering, I still take a great deal of comfort from escaping into Narnia. So where does that leave us? I guess I would choose Narnia, but it would be a very, very close call.