It took me about 72 hours to get through Dragon Quest IX: Sentinels of the Starry Sky, though I doubt it should really take someone that long to get through it (I spent a lot of time grinding and doing sidequests. I hear 60 hours is a bit more reasonable, but I can't be sure.
Sands of Destruction (Nintendo DS) took about 19 hours, and that was even with about an hour of unnecessary grinding.
Though, at the same time, perhaps even more may have been necessary.
(PSP) Dissidia: Final Fantasy (on Casual Mode)- About 13 hours to defeat the final boss (Chaos of Shade Impulse).
(DS) Dragon Quest V: Hand of the Heavenly Bride- 23 hours.
PSP
Star Ocean: First Departure- 20 hours.
Star Ocean: Second Evolution- 20 hours.
360
Star Ocean: The Last Hope- 40-50 hours.
DS
Fire Emblem: Shadow Dragon- 15-20 hours.
Dragon Quest IV: Chapters of the Chosen- 20 hours.