FFX took me ~3 months on and off to finish. my save game is around 100 hours. i was new to RPGs at the time so half the time i didnt really know what i was doing or where to go.
the longest it took me to finish a game playing (nearly) non stop was twilight princess. it took me 3 weeks playing every day for 2-5 hours. no strategy guides/walkthroughs except for the forest temple puzzle with the statues. i finally gave into a walkthrough after an hour of messing around with it.