Dragon Warrior is a must play.

I guess you can do the Final Fantasy series, though it's all crap so I don't overtly recommend them.

Illusion of Gaia for SNES rocks.. though you don't want any for that :p

Hrm.. Shining in the Darkness for Genesis is a fine one, though not the greatest.

Legend of Legaia for PSX is good
Star Ocean: The Second Story for PSX is great

Can't think of anymore.