I never actually played all the way through any of them, but I had the first game way back in the day, and the title theme song still makes me feel all nostalgic.
I've never played any of the Phantasy Star games before, but I've always wanted to. I'm probably going to get the Sega Genesis Collection for the PSP within the next week or two, and I'm excited to finally be able to see what the series is like.