Ok, Seldane, already know your answer, cuz you're wierd. Especially since you like the weakest game of the 3 the most! Anyways, the 3 games are Ys 6 Ark of Napishtim(the weakest of the 3), Ys: Oath in Felghana(complete overhaul of the Ys 3), & Ys Origin(basically, Ys Zero, everything that happened 700 years ago in Ys).
My personal opinion, is that they rock. For Ark of Napshtim, it's a good start, it's a great game, & it explains where various things, come from, like what the Black Pearl is, & what Galbalan is. It ties most into Ys 3 I'd say. But, I like Ys 1 & 2, & 4 more then anyother Ys games. However, that changed once they released Oath in Felghana! Fantastistic game that sucks you in, even if you're not a fan of the series(as I now have made new fans of the series

), short, like every Ys game, but sweet the entire way thru, & explains alot more about Ys 3 & ties more into the rest of the series! And, the soundtrack, I've decided is ultimately better then Ryo Yonemitsu's version we got with our Turbo CD Ys 3. And lastly, Ys Origin, which I played thru with Yunica Tobah, & am now playing thru it as Hugo Fact. And, it's just a fantastic game, & even though it's still in japanese, I'm understanding more about Ys, Eldeen, the goddesses, etc. And it probably has my favorite Ys soundtrack ever! Especially a certain final boss song, with uh, I don't want to spoil.
Oh, & to clarify, THEY ARE NOT 3D! They are 2D, or 2.5D if you want to get techical! They are still overhead view, with sprites, that's right, sprites(with exception to the PS2 version of Ark), the scenery is both poly's & tiles, but just cuz' there's lot's of poly's in it, DOESN'T make them 3D! They play like our old beloved Turbo Ys games, but with sword slashing combo's! And I'm not talking like the simple gameplay of Ys 5(for those who hate that game, though, it's a good game, ask Seldane

), it's alot more then that, it's beyond that. The main thing is, you should give them a chance. And, even if they were 3D, who cares, as long as they're fun! Well, unless they were FPSS(First Person Sword Slashing), can't imagine that working, but, anyhoo, those are my opinions. And I thank the Turbo for getting me started on the Ys series, becuase it's now better then ever!