The best songs I think that are from the final fantasies would have to be.....

Final Fantasy VII
Cosmo Canyon
Aeris Theme
Tifa Theme
Crazy Motorcycle
and One Winged Angel.

Final Fantasy VIII
Roses and Wine
Julia
Drifting
Eyes on Me
Love Grows
Salt Flats
and the Successor.

Final Fantasy IX
Melodies of Life
o.o Thats all I know... I lost the soundtrack in tbe post ;-;.

Final Fantasy X
Kilika Sending
Yunas Theme
Rikkus Theme
Ending Theme
Prelude.

Final Fantasy X-2
Prelude
Real Emotion
1000 Words
and the ending songs o.O.

I know thoses only range from FFVII - FFX-2, but thats all I really know XD.