>>57950923 (OP)3 > 1 >>> 2
3's imagery with the crystals, crystal pokemon, and the unown were cool, good fights as well. I've always loved the song in the opening too. https://youtu.be/ezcfgy7y_CQ?t=50
Largely the same for 1 as well, things like pokemon cloning had some funky imagery, I liked that the setting was both isolated and kind of strange, and mewtwo is a good antagonist in the context of pokemon.
I like the music in 2 and the team rocket stuff, but the actual plot didn't feel like much.
I watched celebi and deoxys as a kid and liked them, but haven't watched them since. Never watched any of the others all the way through