For me FFIV and FFVI (haven't played FFV) are the Golden Age for Final Fantasy with their deep stories, wonderful character designs and character backgrounds. With VII, VIII and IX began the down curve. Imo VII was good, but not great, VIII really failed to impress me and I'll probably never finish it, then IX was a short but noticable up curve. X, X-2 (Don't now if I should count it) and XII was what I consider the "Great Disaster" (dramatic :p) with X being a good game but with no character I really liked and far to often having horrible character design. With X-2 the series dived (The battle system was fluid, I liked the jobs, but that was the only thing I really liked about it), and then came FXII, a game that doesn't deserve the Final Fantasy name at all. Crystal Chronicles deserves it more...
I think one of the reasons for my negativity towards some of the later FF's is about disappointment. With the PS1 we got 3D models,FMV and longer cutscenes (we also got long and tiresome battle animations but that's another story :p) and continuing with PS2 we got better graphics which mean more detailed characters. The problem is that even though the characters have more detail than the 16-bit games (FFIV has horrible graphics even compared to other 16-bit games) I still feel much more for the sprites of IV and VI despite the low level of detail.
Oops, a little bit of topic, I'm sorry :P
OT:
As previously mentioned it's difficult to compare these characters. But Link doesn't even sigh when going out to repel evil so I go with him :)
