I LOVE 358/2 Days. Yeah, the mission system can get repetitive, but I just have a lot of fun with the replayability of going back with new abilities to collect all the emblems or treasures. And there are a lot of cool bosses or uniquely structured missions to keep you going. Plus, as others have mentioned, the story is the real draw here. Being placed within the Organization is such a great premise, and the structure of the game allows for more deep dives into the relationships between characters and their headspaces, which I love. This game's got some of my favorite moments in the series, especially with Xion and Axel. I so wish they would've remade this for the 1.5 Collection, it deserves more recognition.
Also, I never gave my thoughts on Pokemon Platinum since I voted for that, but Platinum is pretty close to the top of my Pokemon list. It has such a great balance between new designs, post-game, region design, etc. I also just have a lot of nostalgia for it because it was probably the height of my multiplayer Pokemon experience with my high school friends. A lot of fun times trying to build teams together, breeding, trading eggs, battling, all the stuff. Hoping the eventual Gen 4 remakes will live up to my time here in some way (and hopefully mark the moment when Pokemon games on Switch look nice).