Depends. I mean, obviously something like the NES Final Fantasy titles aren't as good as anything that followed. No story, tinny and short songs, the barest minimum graphical representation. The gameplay is decent, although it's not the most intuitive or user friendly. I stress making a game user friendly is not the same as making the game easy!

However, if you look at the titles relatively as products of their era, the NES titles are comfortably some of the best games of their time with the technology available to developers. FFXIII is probably the worst by those standards. I would not find a place for it in the top 10 or probably even top 20 games of that console generation while I easily could for most of the other Final Fantasy titles.