Also good are the basic Dr Seuss ones. The ones with blue or green on the spine. When writing them he went by the principle of using sight words - he had a list of 200 (I think!) to choose from, and would allow a certain number of extra words per book. Ones like "One fish, two fish, red fish blue fish" and "Ten apples up on top" are favourites here. DD likes them better than others because she not only understands them, but finds them funny.