At least the vast majority of them, I only haven't watched the Sub-Zero movie that follows with TAS
Here is how I rank them:
1. Under the Red Hood: I can't tell how much I enjoy this movie, it made me love Jason as the Red Hood, though he felt a bit too attached to Bruce Wayne, like a baby attached to a pacifier
2. Return of the Joker: Batman Beyond is a Spider-Man cartoon executed better than all of its predecessors, and the movie is not a dumbed down story just rushed to insert Joker in the future, I love the story of his death. I'm not saying what I feel I might be irked of
3. Gotham Knight: Not the entire movie, only the "Working Through Pain" short, it's the best, and is actually touching
4. Mask of the Phantasm: Second best origin story of Batman, still nothing is superior to Batman Begins as an origin story to me
5. Public Enemies: I freaking love Superman, and I freaking love the story it's based of, I feel this adaption is done quite better than the source material
6. The Batman vs Dracula: There was a time when I was away from TAS, I felt like I hate Batman after reading a few mediocre comics from War Games, and some terrible Morrison stories; R.I.P & RoBW. This movie restored my love for Batman, and I felt that the best Spider-Man voice IMO actually worked fine for Batman
7. The rest of the movies (including the other 5 shorts in Gotham Knight)