Unfortunately, I haven't seen A Star is Born (BUT IS REALLY WANT TO) and this movie is fantastic! It's definitely the most accurate documentary of Judy Garland that we will ever have because it's based off a book written by Judy's daughter, Lorna Luft, who also directed this movie. It shows the tragic life of Judy but also what an amazing entertainer she was with a fantastic personality. If you haven't seen it I HIGHLY recommend it!

Unfortunately, I haven't seen Life With Judy Garland: Me and My Shadow, but I've heard good things about it. I'm interested in it, because Judy Garland is my all-time favorite celebrity.
A Star is Born is a timeless masterpiece (it is a bit long, though)!