I'm in my early 40's and from the time I was little, I remember my mother saying I loved "Goodnight Moon". I remember her reading it to me when I was about three years old, along with "Santa Mouse", "The Very Hungry Caterpillar" and a book called "Heather's Feather's".
So, when I was pregnant with kid number one, I found my original copy of "Goodnight Moon" and read it to him. I read it to each child I was pregnant with, bought it as a baby shower gift for each friend's baby (unless I knew they had a copy).
I asked my 14 year old daughter what her earliest book memory is and she said, "The Lorax". Which is funny because I have a picture somewhere of my husband reading that same book to our oldest child when he was only a week or two old. I also have pictures of my husband reading his finance text books to our oldest child around the same age. I have the question out to my oldest (at college) and he said, "Chicka Chicka Boom Boom" and my middle child (currently in school) says, "Harry the Dirty Dog."
It doesn't matter what you read, just read to them. But know that they do remember what you read from about age three and on so make it a good book or two or ten!