I discovered the Atelier series this summer and, after I watched a video about the various games, I really wanted to try one. I decided to wait until October to get Atelier Ryza and I'm so glad I got it. Atelier Ryza is one of the games I've enjoyed the most and it really made me fall in love with the series.
So far, I played Ryza, Rorona DX, Totori DX and I'm currently playing Meruru DX. I'd also like to try the Dusk trilogy when it goes on sale, since I've heard a lot of praise about it and Hidari's character design and style are wonderful. And also Lulua, to complete the Arland tetralogy.