Yes to Roald Dahl! I have read to ds1: C and the CF, The Giraffe, The Pelly and Me, The Twits, James and the Giant Peach, the BFG, The Enormous Crocodile, The Minpins, George's Marvellous Medicine, The Magic Finger, Matilda, and Fantastic Mr Fox. I am saving The Witches and Danny, Champion of the World til he's a bit bigger (he's 7). And I didn't bother with Charlie and the Great Glass Elevator cos I think it's pants.
Ds1 alos adores Dr. Seuss - though not chaptery, more to be read in one sitting. If you haven't read anything other than The Cat in the Hat, there's a lot more to him than that. Ds1's favourites are:
The Lorax, the Sleep Book, On Beyond Zebra, Oh the Places You'll Go!, the Sneetches and Other Stories, If I Ran The Circus, Did I Ever Tell You How Lucky you Are, I Had Trouble in Getting to Solla Sollew, Oh the Thinks You Can Think, Horton Hears a Who, Horton hatches the Egg, Yertle the Turtle, If I Ran the Circus...and of course the Grinch!
He also LOVES Jeremy Strong - I got a box-set of 8 books for his birthday (from Red House) and we have read all but two now. Ds1 has enjoyed: There's A Viking in my Bed, The 100 Mile an Hour Dog, Fatbag the Demon Vacuum Cleaner, My Dad's Got an Alligator, The Karate Princess, My Granny's Great Escape, My Mum's Going to Explode.
Have just amazoned Jeremy Strong - ooh he's written loads, feel a shop coming on, we just started our second to last Giant Jim and the Hurricane!
While I remember the Narnia books fondly, having re-read them recently I think they are a bit dry and wordy (for my son at least).
Oh and he loved the first three Harry Potters, drifted a bit in the fourth, and we gave up completely on the 5th (not enough Quidditch!)
Sorry, got a bit carried away then - can you tell I was a librarian in a previous pre-child incarnation?