My first memory of Judy was Wizard of Oz, but I think that was only because I could relate to it as a child. She made me feel like I could someday sing like her!
The clips showcase some of her amazing ability but since I was raised on these movies, they didn't change my mind about her. She was an amazing performer in every way. The only film that bothers me was The Pirate, where she seemed hyped up and frenetic in her performances, and not quite in touch with her fellow actors.
Her film, A Star is Born, is wonderful. I get chills every time I see the scene where she spills her guts