I’m pretty split between Clannad and planetarian but ultimately I chose planetarian, solely because I listened to the planetarian bookclub podcast but I have yet to replay Clannad and listen to those podcasts. I’ll just list why those carry the most powerful meanings personally.
Clannad is my favorite anime of all time and the first visual novel I ever played so naturally it carries some significance. Add to that the fact that the focus is on family, something that all of us, blood relation not required, have… I hope. It simply is not possible to live without family. They are the ones who shape your life and your morals which you keep with you even when you leave home or whatever. Also, upon analyzing Fuko’s route, I learned that you will simply find more meaning by observing the story more and more. Since I’ve spent more time on Clannad than any other anime, it is very powerful to me.
I think planetarian carries the most powerful meaning because well… It was the easiest to extract meaning from. Because it is they shortest Key story, it’s easy to reread and focus on certain elements such as the rhetoric. I even used planetarian in some English homework essays like twice. Thanks to the bookclub I realized how easy planetarian was to analyze so I was able take from it the themes of hope for humanity, and to appreciate the little things, like the night sky.