-the bee's knees
For those not in the know the Ys series (pronouced east) is one of the main franchises made by the Japanese game company Falcon (the other major franchises Legend of Heros and Trails series) the latter of which I may delve further into. Excluding the remakes there have been 9 Ys games. In game chronology the order is Ys Origins, Ys 1 and 2, Ys Memories of Celceta, Ys Oath of Felghana, Ys Ark of Napishtim, Ys VIII, Ys Seven and then finally Ys IX.
The games follow the adventures of Adol (and usually his buddy Dogi) who travels to different lands to seek adventure and treasure. Most games are self contained stories meaning it is not strictly neccesary to play games in order as only basic nods are made to previous games so do not worry about having to go on a mad marathon to catch up. All the games are action rpgs but they do have distinct battle mechanics. For example Ys 1 and 2 use bump mechanics while Ys Origins, Oath of Felghana and Ark of Napishtim utilise a battle system that more closely resembles action combat. The final four games: Ys Seven, Memories of Celceta, Ys VIII and Ys IX deploy party based action combat. I can't speak for all the games as I have only played three games in this series (those are Memories of Celceta, Ys VIII and Ys IX) but all these games are enjoyable. Any how I would recommend playing those games and will post some reviews of these games.