>>57290560never actually answered this.
honestly? the spritework is super unique for the series, with the style never really appearing again, so it ended up being the "magnum opus" for it. it has some sense of cleanness and simplicity to it all. that, alongside the weekly events, the day/night cycle, the pokedex being filled with 80% bangers, AND the inclusion of the pokewalker in HGSS, means that it had quite a lot of good going for it! not to mention that going to other regions is such a big thing for the fanbase because of these games.