You spelt Tidus wrong. XD
Anyway, the only systems I have are handhelds. I used to be a big FF-hater, but that was before I got it to try it out (Golden Sun lover am I). #5 was my first, and favorite to date, because the job system made it feel like it wasn't a total departure from unfamiliar territory.
I own the following:
#1 Dawn of Souls (finished the game)
#2 Dawn of Souls (on and off in progress)
#3 DS (used to have, finished it, then sold it because it sucked)
#4 Advance (finished the game)
#5 Advance (finished the game)
Dissidia Final Fantasy (for the most part, finished it)
By 'finish', I mean a literal 100% of the game, not just beating the final boss. I would get #6 to play that, but I haven't been able to find it at Gamestop anywhere.