hmm, might as well put everyone, but these would be my most wanted.
Vincent
Nanaki
Advent Children Barret
Smoking, cursing Cid
Kadaj, Loz and Yazoo
The Turks
Zell
Rinoa
Irvine
Older Siefer, Fuujin and Raijin
Younger Squall (KH2 Squall seems older and doesn't say "whatever")
Summoner robes human Yuna
FFX Human Rikku
Older Tidus
FFX-2 Human Paine
Lulu (They may have to make her outfit more family friendly though as well as no more bending over -_-)
Kimahri Ronso
Older Wakka
Unsent Jecht, Braska and younger Auron
All the Aeons as cameos
Bah, thats just about everyone Nomura designed XD