I have always preferred "real" books. It's nice to have something to hold, pages to turn, a physical object that can be lent to friends, or something that can be picked up another time to read again. A nicely illustrated book is a work of art that cannot be appreciated on a small screen.
I was actually quite anti e-books until I went on holiday with some friends who had Kindles. Those of us with paperbacks had terrible trouble with pages blowing about in the wind, and the glue that held the pages together actually melting in the heat so pages were coming loose. Those with Kindles sat quietly and smugly getting on with their downloaded novels! So - I can see the benefits in such circumstances.
But that's all very well until the battery runs out, or some technical problem occurs. Also, I don't really like being surrounded by electronic equipment all the time. It is like a kind of electrical pollution. Have you ever noticed how quiet and peaceful it is when there is a power cut, and all the humming, noises and artificial lights and so on have stopped? Give me a nice quiet book anyday!