I was an Education major in college, so I absolutely love childrens books. I don't have any kids myself (and never will... I don't want any) but Children's suthors are the best. Scott O'Dell, Kathryn Patterson, SE Hinton, people like that are my favorites.
Other than that, I love Margaret Atwood, Jean Plaidy, and Laura Esquivel.
Not to mention poetry: Dorothy Parker is my fav. I also like Emily Dickinson and Langston Hughes.
Plays: Tennesee Williams, Sartre (sp??)
And of course Emerson, Thereau, and all those guys.
Sorry. but I love literature. I know these are not "series" authors but I thought it would be okay to post them anyway.