5. The Place I'll Return To Someday (FF9)

You boot up FF IX and what do you hear? This track which doesn't only sell you on playing through the whole game, but also sticks with you while you do it. Almost, just almost the best prelude track in FF.

4. The Stage Is Set (FF8)

Great track to get motivated to do something and also potentially the best military song ever. 'Twas for a while my second favorite FF track, I just listened to it all the time and never got bored of it which not many tracks/songs manage.

3. The Castle (FF8)

Hands down best organ track in FF. It has so much variety and calls forth so many different feelings, making Ultimecia's Castle really stand out above all the other areas in this game.

2. Someday the Dream will end (FF10)

Beautiful track and I really love that this track plays nonstop in the Ruins of Zanarkand up to the Dome. It captures the emotions of walking through a destroyed version of your own home nicely but it doesn't go overboard in doing so.

1. Ending Theme / To Zanarkand (FF10)

To clarify, I think the Ending Theme is better, but only because it includes beautiful rearrangements of To Zanarkand, which would've otherwise taken the Nr. 1 spot. I didn't want to have the Top 2 Songs just be variations of each other so I gave them the top spot together.
These tracks are just outright amazing, wonderful to listen to and I find myself whistling the melody more than anything else. Ending Theme is probably one of the main reasons why I love FF X's ending so much. And To Zanarkand plays prior to starting the game. Now THAT is how you start and end a game right there!

FF7 only made it in the 7+ spots (how ironic) so no place on this list. They're not bad, they just can't keep up with the other awesome musical pieces in this amazing series.