7,9,6,8,3r in respective order. I played the older games when I was a kid and was too noobish to be able to understand and hence appreciate them. I tried playing the old games again but it was just a tad too outdated except for the 3 remake.
Q6600@3.4 / 295 GTX / AsusP5WDH/8GB Corsair DDR2-800,26" VS LCD,55" 1080p 240hz Samsung LED /PS3/360/Wii/Xbox/PS2/GC/DC/PS1/Saturn/N64
There is no 'best' for me. There are worsts, though.
I cannot stand XII or XIII, at all.
XII, I mostly couldn't get past Vaan being totally pointless.
XIII, it was a linear snorefest, I disliked all the characters except Sazh, And I felt like the battle system was focused less on doing anything interesting and more on spamming autobattle and paradigm shifting.