Pinka/Purple/Golda/Silverlicious. Just discovered there's an Emeraldalicious or something that we haven't read yet
All of the Olivia books, of course (one of my girls is named Olivia).
The Fancy Nancy Series
Sugar Would Not Eat It
They got this for their 4th birthday and love it.
Cars and Trucks and Things that Go
I never had this when I was a kid but a friend did and I loved it. I made a point to make sure my girls have this and they love it, too.
They loved this one when they were younger. Kayley called it "the flea book" and loved to find the flea on every page.