Take my opinion with a grain of salt, for the most part, I’ve mostly enjoyed games released in the third generation and didn’t touch anything past the seventh. The increasing amount of handholding turned me off and degrading mega evolutions from the once advertised evolution of the gameplay formular to a mere gimmick broke the last straw.

That being said: The Gamecube games hands down. The intro cutscene to Colosseum has more story than some generations did in their entirety and instead of you just stumbling into the plot you are actually an integral part of it. As an added bonus, both games feature final bosses that actually fight back. I think Colosseum is the only Pokemon game I ever struggled in.

Of course, taking everything Pokemon into account, Mystery Dungeon is the only true answer, but I wanted to got with an traditional RPG first.

If you insist on mainline games, you’re probably right about the fifth generation. These games have everything you would need, but the execution itself is fumbled - and it has to be, since they questioned their own franchise at its core. Logically speaking, N is right and everyone else is wrong.

There are some interesting things in other generations, but it usually feels tacked on and isn’t actually relevant for 95% of the game. Like, the sixth generation had some nice ideas - but they are mostly implied or retold, without you having any urgency in the matter. Once again why I chose the GC games, two of the few games with you being part of the plot. In the early mainline games, you mostly happen to be there when story happens, in the later games, you sometimes only get told that story happens somewhere.