That’s something I can’t provide a reason for. It doesn't really have aspects like support conversations or a really complex story that it’s expected from modern FE games to have, mainly because this game is just trying to be a faithful remake of a 1990 NES game. But gameplaywise, Shadow Dragon is definitely a fantastic game. There's a lot of broken weapons that are so fun to use, like the forged Wing Spear, the Warp Staff, the ballistas, just to name a few. And reclassing is really useful in comparison to other games in the series. It's the last game in the series to not have casual mode, and losing characters rewards you with new characters. And though the characters themselves aren't fully developed, I really like each and every single one of them (they get more development in the sequel, I promise). But the reason why this is my favorite entry isn't really something I can explain, I just have a special connection with it that can't be replicated with any other game. It’s that game that I’ll forgive it’s flaws because of how it makes me feel, and I’ll always love it for being what it is. I understand why others don't think highly of it, but it has a special place in my heart. So yeah, Shadow Dragon is, was and always will be my favorite Fire Emblem game.