NES
Final Fantasy 1, 2 and 3 - As you can tell by the fact FF2 is also my worst NES RPG in the other thread, these are the only thee RPGs I played on the NES.
That said, there is of course merit to them even without competition. They were generally enjoyable and the foundation of many RPGs.

SNES
Secret of Mana - My first RPG, naturally it holds a special spot for me. This may seem odd given my comments on the remake in the other thread, but context matters, and in the context of SNES games, I'm still perfectly okay with Secret of Mana's issues.

Final Fantasy VI - One of my favorite FF games, certainly my favorite SNES FF. Not much to say here, really, it's FFVI.

Tales of Phantasia - The first Tales game, and it still holds up well too. Laid the foundation of one of the long-running RPG series I really like, and also just a very solid game.

Gamecube
Paper Mario: The Thousand-Year Door - An excellent RPG, it's also my favorite Mario game. It took what I liked about the first Paper Mario and just improved on all aspects.

Skies of Arcadia - Just an entertaining sky pirate romp wrapped in RPG gameplay. Solid, fun game.

Baten Kaitos: Eternal Wings and the Lost Ocean - This interesting little gem was actually developed by Monolith Soft, of Xeno fame. Rather than being the protagonist, you're actually a guardian spirit that guides the protagonist and the protagonist even interacts with you. The battle system used a deck of cards that you customize yourself. Overall I really enjoyed the game.

Wii
Xenoblade Chronicles - While I never finished it because I burnt myself out on the stupid amount of tiny fetch quests (which I still think is the worst part of the game, I know it's optional but hey, I don't decide how my brain works ), it's still a great game. I enjoyed the combat, the music's great and the world's locations are just incredible.

Muramasa: The Demon Blade - A fun little RPG by Vanillaware, who also made Odin Sphere. It's about what you'd expect from those developers, very entertaining 2D side-scrolling RPG action. I didn't think it was as good as Odin Sphere, but a good game regardless.

The Last Story - Much as I like to make fun of this game's story and its laughable romance, I did like the gameplay a lot.

Switch
Xenoblade 2 - As with the first Xenoblade, I still enjoy the combat (moreso, even). It also wasn't bogged down by as many pointless fetch sidequests, instead having fewer but more interesting sidequests. Most people bash on the Blade system in this game for its random-ness, but I can live with that, it never really got in my way. Locations are just as great as in Xenoblade 1 and I liked the story as well.

Octopath Traveler - Overall an enjoyable game, with gameplay similar to Bravely Default. Not an especially intriguing story, but it's sufficient. My biggest issue with this game is that it's just not very compatible with my playstyle, which is to hoard items and MP. This game's random encounters won't really let you do that unless you vastly outlevel enemies, which makes playing this game a not so relaxing experience for me, constantly having to against my instincts.

Fire Emblem Three Houses - After two Fire Emblem games that I disliked, this entry took the series to a place that I enjoyed again. The battles are pretty standard Fire Emblem fare of course, with the addition of a rewind function that's convenient to have. Good music, story's not that great but serviceable. It did start to wear on me a little near the end, where I started to just skip weeks to get to the next story section.

Xbox 360
Lost Odyssey - An amazing RPG that deserved more success than it ultimately got. Interesting story, gameplay similar to Final Fantasy X and great music. If you're able to play this game but haven't, do eet.

Mass Effect 2 - My favorite entry in the Mass Effect franchise. It streamlined and polished a lot of the things I had issues with in the first game. Also, shout-out to the Suicide Mission, which to this day is still Bioware at its best.

Resonance of Fate - A very solid RPG with unique gameplay. The overworld consists of hexagons that you have to fill in (with various effects) before you can traverse them, and the combat is a semi-turn-based run and gun system, where you can pick a location to run to, and as the character is running there you can jump and/or shoot enemies and set up combinations with multiple characters. The game's only sin is the tutorial, which is just walls of text that make no real sense until you actually try things in combat.

PSP
Trails in the Sky FC - A great game on its own, but also the foundation of an even greater overall series. Music, story, characters and worldbuilding are all great. Combat wasn't quite up my alley yet in this entry because it's a bit slow and punishing, but it was still enjoyable combat.

Kingdom Hearts: Birth By Sleep - Still possibly my favorite KH game. I love the command deck, the tragic story and the combat. Having to go through the worlds with each character could at some points be a drag, but it was overall fine.

Persona 3 Portable - Persona 3, but with female protagonist. What more is there to say?

Playstation Vita
Ao no Kiseki/Trails to Azure - This game's pretty high up there in my ranking even among Trails games. Great story with some incredibly intense boss battles, and well, everything else is also great as usual.

Zero no Kiseki/Trails from Zero - Less intense than above entry, but almost just as great nonetheless.

Ys: Memories of Celceta - My second-favorite Ys game. Just a quality action RPG. Fun combat, great music.

Gameboy Advance
Super Robot Taisen: Original Generation 2 - One of my favorite entries in my favorite SRPG franchise. While most Super Robot Taisen games are crossovers of various licensed mecha series, the Original Generation games take original characters from these crossover games and make *them* crossover with each other in its own original premise. It's actually a pretty good story, but of course the main draw is the mecha battles wrapped in an enjoyable SRPG combat system with great music.

Golden Sun - A solid RPG overall, but what made it stand out to me was its dungeons, carefully designed, interesting and filled with puzzles.

Golden Sun: The Lost Age - The sequel to Golden Sun, and no less impressive. I'd say this one's even better.

Nintendo DS
Radiant Historia - A great RPG with a sort of grid-based turn-based combat system and an interesting time travel story filled with characters I liked.

Ys 1 & 2 - That's right, I actually played the DS version of Ys 1+2, which rather than the bump combat had a more standard "press this button to swing sword" combat.
Again, just an enjoyable action RPG.

Dragon Quest V - One of my favorite Dragon Quest games. The combat is your standard DQ fare, and the story ultimately isn't super intriguing or anything, but something about the way it covers the protagonists childhood, teenage years and adulthood stuck with me.

Nintendo 3DS
Shin Megami Tensei IV - Possibly my favorite mainline SMT game, hard to tell if it beats Nocturne. Either way, it's a great RPG that takes the familiar SMT gameplay and streamlines it a little bit further.

Shin Megami Tensei: Devil Summoner: Soul Hackers - Not as good as SMT IV, but very enjoyable still.

Kingdom Hearts: Dream Drop Distance - Not exactly my favorite Kingdom Hearts game, but it's still a solid action RPG.

Playstation 1
Xenogears - Still one of my all-time favorite RPGs. The story was completely beyond anything else at the time and the combat was fun too.

Final Fantasy IX - My favorite single-player FF.

Legend of Dragoon - I really enjoyed the combat and how your attacks got stronger depending on how well you performed the timing aspect of it. Also, as campy as the story and characters were, I loved it anyway. The music was great too.

Playstation 2
Ar Tonelico - The game that changed my view on game music and how intertwined with the game's story and themes it can be. It's also just a really good RPG.

Ar Tonelico 2 - Even better than the first game (and future installments), this game was just damn amazing. I loved the music, the story, the characters and the gameplay. Just thinking back on the game puts me through an emotional rollercoaster again.

Super Robot Taisen Alpha 3 - Honestly, I could put a dozen other RPGs in this spot. All of them were great but none really left that lasting impression on me like the above two entries. Anyway, this game, as I said previously in this post, is a cross-over game with a bunch of mech series wrapped in SRPG gameplay. You want to see Gunbuster, a plethora of Gundams and Evangelion units fighting space bugs side by side? Then this is your jam. It's definitely mine.

Playstation 3
Trails of Cold Steel - A big step in the evolution of Trails, this game streamlined the combat a lot and also made the step to full 3D. Again, the world, story and characters are great.

Trails of Cold Steel 2 - See above, but I liked this one even more.

Ar nosurge: Ode to an Unborn Star - The (sadly) final entry in the Ar Tonelico universe, it's just as great as the Ar Tonelico games. Again, amazing music, fun combat and a good story. Again, thinking back on it is like an emotional rollercoaster.

Playstation 4
Trails of Cold Steel 3 - My second-favorite Trails game. I feel like I don't really have anything to add on top of what I said about previous entries on this list.

Trails of Cold Steel 4 - And my favorite Trails game (also, y'know, my all-time favorite game), acting as a big climax and wrap-up of many of the story elements of the first three Trails arcs (which serve as the "first half" of the series overall, hoo boy). A pretty massive endeavor and I loved every minute of it, including the ending that actually completely nails it in my opinion.

Ys VIII - An amazing action RPG and a step above even other Ys games. It's just pure fun to play and even delves into the story and characters more than previous entries.

PC
Deus Ex - A game that completely blew away my expectations and still stands as the pinnacle of western RPGs for me. It very much changed my view on certain aspects of RPGs.

Trails in the Sky SC - Well, at this point I've gone through enough entries in this series throughout this post. All that stuff applies here too.

Trails in the Sky the 3rd - And again. although this one has a very different structure (more a dungeon crawler with some long text-heavy sections inbetween), I still love it.