1. Symphonia is my favorite, a still pretty solid action RPG, and unmatched by the rest in terms of story, and managing to pull off a fantastic, well rounded cast of 9 playable characters, plus a really good antagonist, which is something the series generally fails at. Memorable music, a good set of dungeons, lots of great side events and quests, and with for the most part very consistent writing with the skits. Best RPG for me.
2. Phantasia is a fantastic game, it has aged in the combat for sure, but I was still impressed by how much it sets up for the series, the action combat, the themes and story tropes, and focusing primarily on developing the party's chemistry. Played it fairly recently and is still was a very engaging, magical experience, closest to Symphonia in that sense.
3. Vesperia/Eternia/Abyss. All amazing games, cannot really pick one over the other, they all have great combat, Abyss has an amazing story, Vesperia a great cast and a good feel of adventure with one of the best Tales scores, Eternia is the best of the PS1 games, a nice journey with a more intimate chemistry with its 4 characters.
4. Xillia 2/Berseria. PS3 is where Tales of starts to feel more empty with its areas, cause the bigger overworlds don't really offer anything substantial compared to the older games, costumes start to get locked behind paid DLC, the dungeon design doesn't feel as tight most of the time because again, they have to be bigger just because. The main combat that started since Phantasia peaked with the Xillia games, Xillia 2 fixes a lot of issues with the first game, and it does one of the greatest stories of the series, they even fixed Leia. Berseria is a good prequel to Zestiria, and it elevates itself and that game when one plays both rather well, the combat is fine, but again it has a really good story and cast of characters, tho some of the skit tropes can be repetitive.
5. Xillia/Zestiria. Xillia feels incomplete, it has some neat ideas, but once the ideas start gaining steam, the game sort of just ends, the combat is amazing, and Fenmont is one of the few, really memorable locales the series got post-Vesperia, amazing combat too. Zestiria is a weird game, it feels underdeveloped with a lot of its characters, but still feels like an entry with a lot of heart into the story and character dynamics, has a mostly good music score, and brings 5 really good dungeons with it, the combat feels like a more sluggish version of Graces' combat, but still pretty fun.
6. Tales of Destiny. The story and characters are mostly unremarkable, should have really lean back on the amount of characters for the time, it only really has one memorable moment that stands on its own, the rest feels pretty standard Tales of, which is still a good time for me, but I can't find much worth of noting with it.
7. Tales of Legendia. Is an interesting game, the character interactions are pretty great, the music score is fantastic, the divide of having a main story and then have the character specific episodes play out separately is an interesting choice, but what brings it down a lot is the combat, the worst feeling of the series for me, feels floaty, most artes lack impact and flow to them.
8. Tales of Hearts R. The story and characters actively annoy me in a lot of moments, when Tales of makes romance a main focus is always pretty bad, I like the idea of the emotion dungeons, but the design leaves a lot to be desired, the main dungeons themselves are fine tho, but it has great combat with a neat addition of parry.
9. Graces F. It has fun combat, but everything else is just plain bad, the characters are bad, the story is bad, the music is forgettable and is not even that fun to listen to in game, the romance and friendship aspects suck, the final dungeon is a test of patience, and I just didn't felt like continuing the Future portion after getting annoyed at one of the bosses. I would still probably play it at some point again just because it has a pretty unique combat system compared to the rest of the series, even if Zestiria imitates some aspects of it.
I have yet to play Destiny: Director's Cut that recently got an english patch, and Innocence. Destiny 2 is getting an english patch soon, and I hope Rebirth also gets one someday, so I can complete the main series.
I don't count Dawn of the New World as a Tales of game, doesn't deserve the name, and neither does it deserve being a sequel to a game like Symphonia.
Bonus: I hope Tales of Arise is pretty good, everything I have seen doesn't really make me excited besides knowing the fact is another game from my favorite RPG series, I feel if I was someone that didn't knew about Tales of, Arise wouldn't convince me to get into it, but again I hope is a pretty good game, Tales of is a series I hope to never get tired of playing.
One of my wishes was that hopefully the costumes would be implemented as side-quests and rewards through gameplay again, but from seeing the digital deluxe editions my wish won't come true, they are even locking cooking recipes behind it now YAY, but costumes are just cosmetics so I shouldn't care.