I prefer games that offer things for the player to do, especially
in post-game. Or have a decent difficulty while playing. I grew up
with Gen 5 so I'm a bit biased I'd say to that generation hahah.
Really all I do is either shiny hunt or IV hunt my favorite pokemon
^^
My favorite has to be emerald, the mons, map, battle frontier, and
many tinier things like Mr. Briney and Peeko or the absolute
hilarity of everything Team Aqua and Team Magma do. Platinum and
Black/White do definitely follow right behind, mostly for story
like you said, but I've also gone too long without replaying them
as well as consumed too much fanfiction and fanart of both to have
my opinion be of the actual game instead of what the internets
filled my head with. I never got a 3DS to play generation 6 and up,
but I can respect it for the mega evolutions and some very pretty
scenes.
But since you prefer the story Allspar I'd very highly recommend
Legends of the Arena, the gameplay is very well
done and definitely not easy too so what I'm saying is the entire
thing, not just the story, is amazing.