FFVII is the only one I managed to finish, haven't played it for a long while though. I seem to remember there being an ingame timer of 99 hours then it stopped. Mine was on 99 for weeks before I finally managed to complete it (not 100% of course, if anyone ever did?) I used to love leveling up, try and find somewhere that would give decent exp points and spend a few hours a night grinding away.
the timer on ff8 went red after 99 hours i think and counted as zero again, or something
which was a nice addition. 7 was the best, infact im replaying it now. damn i love this game. i'm up to the part just getting past the chocco farm, and avoiding the midgar zolom 



I know it's second last on my list but they're all very close in rankings imo.