Pokémon games tier list explanations of rankings are below: (warning: holy yap)
S Tier
(S+) SV is peak. I'll save you the essay, and just say I love everything about it (except trade evos and version exclusives but that's unfortunately a constant with these games).
A Tier
(A+) LZA is also very fun, loved the new battle system, and ill probably keep shiny hunting for a while. Narrowly missed S tier because some of the requirements for the shiny charm are crazy, they kept trade evos for some dumb reason, and the battle pathfinding can sometimes be weird. These issues come up a little too often for me to say S tier. Otherwise great game.
(A) BW is also pretty nice. Granted, I haven't played it in a bit, but they integrated HMs better than any other game and the regional dex is very nice. Doesn't do much wrong, but doesn't do much incredibly either. That being said, having little flaws lands it comfortably in A, though just a couple steps from A+. If it had modern QOL improvements, could be S tier.,
(A-) SwSh was my pokemon game I fully played, and looking back my standards were pretty low. I didn't really have issues when playing, and the DLCs boost it to A. Maybe a replay could do it some justice in my eyes.
B Tier
(B-) HGSS was really good until half my playtime became grinding up my team. They weren't lying, the level curve sucks ass. Ruins what could've been an A or A+ tier game. But what if I told you it actually gets even worse? HMs in this game feel like such a pain in the ass here, especially post-gym 8. In addition to this, as someone who really values when these games have their own unique identity and features, it felt so disappointing see so much of this game's regional dex and story significance given to Kanto and the original 151. Like I know Johto was a literal sequel to the gen 1 games, but I'm playing this in 2025, not pre-9/11. Are you ok Johto? Why are you afraid of having an actual unique identity? I don't know where else to put this, but the game is really pretty.
D Tier
(D+) RS was a jarring experience. The HMs, the lack of the physical/special split, all of this just sucked, especially since everyone hyped this up as one of, if not, the best generations in pokemon history. I can see why people at the time liked it, but I am not of their time. I play games to have fun. I don't find having to massacre my party's moveset for the sake of basic traversal to be fun. I don't find the elite 4's level curve to be fun. I don't find exploring an ocean of tentacruels to be fun. And I especially don't find my team's physical attackers being forced to use special moves simply due to their type to be fun. There were some nice moments, especially the regional dex, hence why it's not F tier, and I do admit I'm probably doing it a little dirty since it was my first pre-gen 5 game. And yet, I cannot bring myself to care, nor ever touch a gameboy pokemon game again. I've heard good things about emerald, but looking at the changes, it's not enough. ORAS looks alright, though.
That was my list, or at least the ones I've played. I've got my eye on other games, so I might update this list in the future.
Feel free to comment if you agree or disagree, or don't, I'm not your dad.