I've got problems sleeping and something I tried the other night helped quite a bit.. I opened up winamp and loaded all FF9 songs into the playlist. I deleted all the ones I found too loud and non-relaxing.

This was my list.

Jesters of the Moon
Memories Erased from the Storm
Vivi's Theme
Vamo Alla' Flamenco
Stolen Eyes
Your Warmth
Awakened Forest*
Memories of that Day*
Eternal Harvest
Frontier Village Dali*
Ice Caverns*
Limited Time*
Song of Memories*
Aloha De Chocobo
At South Gate Border
Fairy Battle
Burmecian Kingdom
A Face Forgotten*
Garnet's Theme*
Cleyra Settlement
Extraction
Loss of Me
Fossil Roo*

These songs all helped me sleep but the ones I found most effective are the ones with * beside them

My Favourite 2 would have to be Awakened Forest as that was like a constant lullaby to me, and helped me drift off quite suddenly.
Memories of that Day also calmed and relaxed me.

I know it may sound strange but if you have these songs and do find trouble sleeping, it may be worth a shot. There are some songs like this in all final fantasies, you just have to find which ones relax you most