My girls loved the Sandra Boynton books as young toddlers. At two, DD#1 memorized our collection and would sit in the rocking chair "reading" them to her baby sister. They also really enjoyed Dr. Seuss.
When they were about preschool age, Berenstain Bears and Magic School Bus were favorites.
I started reading Harry Potter to them when they were three and five. Both girls were more than willing to sit and listen to a chapter a night. I only read the first three books at that age though. I was worried that the content was getting too old and scary for them.
