Judy Garland was a fascinating character - the ineffably innocent girl star of The Wizard of Oz who died a junkie, the golden girl of American showbiz who became a monster to work with, MGM's biggest moneymaker who ended up almost unable to afford to feed her own children. Like the other two great failures of the twentieth century, Elvis and Marilyn, a kind of mythology has grown up around her - most famously, she was the model for Neely, the child star who became a showbiz legend in Jacqueline Susann's sixties cult classic, Valley of the Dolls. Gerald Scarfe's biography of her, Get happy, tries to examine the person she really was beneath the legend. 
Unfortunately, it's not a great biography. It's well researched but ultimately unsatisfying - and this within a genre, biography, which is by definition unsatisfying (who can really tell about someone's life from the outside?) It's muddled, messing up the chronology in small but inexplicable ways, jumping between different people's views of the characters without ever trying to resolve the contradictions inherent in these, giving a generous interpretation of someone's actions on one page and tearing them apart on the next.
Judy is totally fascinating though. The life of the MGM star reminds me very much of what you read about Elvis: to a certain extent they are pampered, indulged, kept sweet, but at the same time their lives are completely controlled, their telephone calls and telegraphs monitored, even the decision of whether and who they can marry is evaluated on a purely commercial basis. It would make a great film - if anyone could ever make it.