In order to "celebrate" Jessica Simpson's big screen debut (it's tomorrow, boys -- hopefully you can keep your pants on until then), Entertainment Weekly has put together a definitive guide to divas past and their celluloid debuts. Diana Ross' turn as Billie Holiday in Lady Sings the Blues gets the highest grade; it's probably no surprise that Miss Mimi performance in our favorite "crapsterpiece", Glitter, gets roundly trashed. Also on the list is Cher's debut, a movie I've never seen called Chastity. Written and produced by Sonny Bono, and tackling hot issues like sex, drugs and schizophrenia, it sounds a lot like Go Ask Alice, except ... it stars Cher.