Do you wonder about the tier or effectiveness of that medal you have just gotten? We have prepared this list for you based on the work of other players. You can easily view the ranking of medals as well as searching for any specific medal. Use this list to determine whether or not to pump EXP medals and munny to upgrade your medals.

RatingMedalAvailable
A+Sora Limit Formx
ALeon [KH2] {ver. B}x
ARiku [KH2] w/ Black Coatx
B+Aerith [KH2]***x
B+DiZ***x
B+Riku [KH2]x
B+King Mickey [KH2]x
B+Riku [KH1]x
B+Vivi***x
BAuronx
BGoofy {ver. B}x
BMushux
BPeter Panx
BSora [KH1] {ver. B}x
BSora [KH2] {ver. B}x
BSora Wisdom Formx
BTinkerbellx
C+Cloud [KH2]x
C+Simbax
C+Stitchx
C+Sora Valorx
C+Tifax
C+Wakkax
CMagician Donaldx
CDonald {ver. A}x
CMulanx
CPainex
CRikkux
CSora [KH2] {ver. A}x
CTidusx
CYuffie [KH1]x
CYunax
CLeon [KH2] {ver. A}x
D+Beastx
D+Goofy {ver. A}x
D+Jiminy Cricketx
D+Selphiex
D+Sora [KH1] {ver. A}x
D+Yuffie [KH2]x
DAbux
DBambix
DDr. Jumba Jookibax
DDumbox
DHaynerx
DPencex
DPlutox
DOlettex
SAxel {SP ver.}
SPooh & Piglet
SSephiroth
SSion {SP ver.}
A+Aerith {Illustrated ver.}
A+Cid {Illustrated ver.}
A+Demyx
A+Donald (Timeless River)
A+Goofy (Country of the Musketeers)
A+Jack Skellington
A+Kairi [KH1]
A+King Mickey w/ Black Coat
A+Lexaeus
A+Mickey (Country of the Musketeers)
A+Minnie Mouse
A+Riku [CoM]
A+Roxas {SP ver.}
A+Xigbar
A+Yuffie {Illustrated ver.}
A+Zexion
ACerberus
ACloud [KH1]
ADonald (Country of the Musketeers)
AGoofy (Timeless River)
AHades
AKairi [KH2]
ALarxene
AMarluxia
AOld Woman
APain & Panic
ASaïx
ASora Final Form ver.
ASora (Timeless River)
AXaldin
B+Card Soldiers
B+Donald {ver. B}
B+Evil Queen
B+Hercules
B+Pete (Timeless River)
B+Queen of Hearts
B+Riku [KH3D]
B+Sora [KH3D]
B+Sora Master Form ver.
BAerith [KH1]
BAlice
BDaisy Duck
BLuxord
BMeg
BMeow Wow
BNamine [CoM]
BPhil
BWhite Rabbit
C+Donald (Halloween Town)
C+Goofy (Halloween Town)
C+Sora (Halloween Town)
C+Sora (Halloween Town Santa)
CAladdin
CGenie
CGoofy Knight ver. (Captain Goofy)
CVexen
CYoung Hercules
CZack
D+Cinderella
D+Jasmine
D+Mickey (Timeless River)
D+Pinocchio
D+Seven Dwarves
D+Snow White

























Source:
This page has been sourced and reformatted, and checked against current available medals as of 4/12/16. The referenced tier list is originally created and shared at This Reddit Discussion/

Reformat Note:
Rating of 10 is S
9.5 is A+
9 is A
8.5 is B+
8 is B
7.5 is C+
7 is C
6.5 is D+
6 is D

Availability
The medals have been checked against current offerings. The full Japanese version is also included at the bottom of the table.

** These medals are end game setups because of their ability to boost the strength or damage of your team.