I will back up HeartGold/SoulSilver as well. Just a perfect modernized adaption of a classic generation, lots (and I mean lots) of content, lots of catchable Pokémon, lots of legendaries, two regions… I think they really hit it out of the park with it. I also personally enjoyed using the Pokewalker to get access to exotic Pokémon.
It’s not completely free of issues (the level curve isn’t the best and - being based on an older game - it’s much less story oriented than later titles). However, I still hold it as one of the best games they ever put out, and a great entry point.
Great writeup. In retrospect it’s absolutely insane how many series-defining features were introduced in Gen 2. That kind of generational leap is mindboggling.
I love your username btw, brings me back to the schoolyard, to Kangaskhans with Fly and rumours of finding Mew under the truck in Vermilion.