Population Growing and Wild World have the most replay value for me personally. The newer games have a lot of interesting features, sure, but I don't play Animal Crossing for its "interesting features." I play it because it fills the hole in my heart, and so far PG and WW have been the only ones to do that for me. I want to like New Horizons, and it might eventually grow on me, but it's missing that "it" factor the previous games had. It feels like a sequel. If that makes sense.