>>723503957
FF4 will seem lackluster if you play 6 first. 6 is the pinnacle of the 2D games, scope, art direction, music etc. Both are good though.
7 is the most popular of the psx era but lots of people prefer 8.
I never got into 10 or X series so can't really comment.
If you do like 6, Suikoden 2, Chrono Trigger and Seiken Densetsu 3 (secret of mana) are worth a look.
>>723505076
Pretty much this