It is hard to remember what Judy Garland film I actually saw first. It's like she was always there. Was it the re-release of The Wizard of Oz? Was it Judgement at Nuremberg? More likely is that it was the Andy Hardy movies or Easter Parade on TV. She was ubiquitous in my childhood.
Watching the clips, I find myself appreciating her dancing skills but even more the emotion she brought to her performances. The sheer joy in these performances is wonderful. She always was able to bring the right emotion.
Later films that stand out to me are In The Good Old Summertime, Summer Stock and especially A Star Is Born.