The Sweet Valley Books by Francine Pascal. I know I grew up reading these books and I have to admit sometimes I still will pick one up just to revisit that world and the characters we grew to love.
Sweet Valley Twins and Friends how many of you read this series or your children did? I hope when my littlest one gets older she reads it.
Sweet Valley High Here we got to see the girls starting to really grow up and some of the stuff they were dealing with we were dealing with as well.
There is several more spinoffs and side books but you get the idea of the books. Did you read any of these? What book or series holds a fond memory for you?