This is literally the first RPG I ever saw anyone playing, ever. I didn't know what Hit Points were until I saw someone playing Phantasy Star.
Final Fantasy, Dragon Quest, those became interesting to me later, but in the beginning, I merely was a 6 year old kid safety pinning a towel to his shoulders, picking up a steel shower curtain rod and pretending to be Rolf fighting Dark Force.
That experience has stuck with me for a long time, for you see, I would sing my own background music while doing it, and this is the very first time I ever remember simply coming up with songs out of nothing. I became a songwriter because of Phantasy Star II.
So yeah...it's been 28 years since then, and I have played Phantasy Star I, Phantasy Star II, and Phantasy Star IV through to the end. I dislike Phantasy Star III. I have played Phantasy Star Portable 1, but no longer own a PSP so I haven't played it in a very long time.
This series really brought storytelling to the forefront of Jrpgs. You notice; Final Fantasy plops you down in front of a Castle, Dragon Quest literally just explains the plot to you instantly. Phantasy Star begins with action; Nero is killed, and Alis is given motivation. She speaks. She has a face, and a home, and friends (good old Suelo).
And, further notice; after Phantasy Star came out, the other two Jrpg giants (FF and Dragon Quest) both stepped up their game regarding how they begin their stories. The second game in both series starts with serious stuff going down. I like to believe it's because Phantasy Star invented kicking players in the teeth at the beginning of the game.

Anyhoo, I'm glad to have found a community of people who understand what the heck I'm talking about when I say that Odin and Tylon are the same guy. Cheers!