I have beaten a few Ys games.
Here's how I'd rate the ones I've beaten:
Ys Origin (PC) = 9.5/10
Ys Eternal (PC) = 8/10
Ys III (TGCD) = 7/10
Ys: The Oath in Felghana (PC) = 8/10
Ys IV: Mask of the Sun (SFC) = 5/10
Ys: Memories of Celceta (Vita) = 8/10
Ys V: Lost Kefin, Kingdom of Sand (SFC) = 6/10
Ys VI: The Ark of Napishtim (PC) = 7/10
Ys Seven (PSP) = 9/10
The #1 must play Ys in my opinion, is Ys Origin. It distills everything that's awesome about the series into a lean mean monster mashing machine.
I finished
Seven today and I must say, that I think this was the correct decision in the right direction, because it gives us more characters to play with, while Adol does what he does best: swinging words. I also love
Seven for finally letting me play as Dogi, who was my favorite companion to play with. Nothing beats the big, strong guy, who may be slow, but when he hits, he REALLY hit. Seriously, Dogis special attacks and skills were a godsend for bossfights.
I found the story quite good, too. I think it gets better in
VIII, where they revisit a theme of Seven, but for a first try, this really good. It had a decent build-up for the world and the big twist, you felt for the characters and the ending was touching in this sad JRPG-way, that you only get with JRPG's. It is not as convoluted as
Tales of Symphonia or some of the
Final Fantasy's and I think that is a good thing. One big story, nothing more, nothing less. It has also the best Boss Fight I've fought so far in this series, where it also shows that Adol in a single-adventure could still work.
I think from all the ones I've played (only watched a Playthrough of
VIII, since my Laptop is to weak for it),
Seven is my favorite so far and it makes me more excited for
IX. I believe, if they keep one of the Writers from
Seven and
VIII around and tweak the mechanics a bit (and don't put the next game completely bugged out), that
IX could be awesome. Until then, I will try to play the rest of the series and try to learn not to suck at the bump-combat of Ys
I and
II :D.
My list:
Not ranked:
Ys: VIII (best story, but haven't played it so far)
1.
Ys: Seven (best story and best final boss so far)
2.
Ys: Origin (Has the mechanics of it's predecessors perfected and the three characters motivate to replay the game. But the final boss is a bit easy - but I still have to beat the true final boss, so maybe it will overthrow
Seven)
3.
Ys: Oath of Felghana (Hard, but in a fun way. Good environmental storytelling and it has my second favorite, final boss)
4.
Ys VI (Tried so much new stuff, but wasn't as good at it, as the other ones. Also lackluster endboss and story)