Mario/Sonic X

Version 1

 * Mario as Sonic (Both the main stars)
 * Yoshi as Tails (Both Mario and Sonic's best friends)
 * Luigi as Knuckles (Both important)
 * Peach as Amy (Both love to Mario and Sonic)
 * Birdo as Cosmo (Both love to Yoshi and Tails)
 * Rosalina as Cream (Both love ice-cream)
 * Yoshi Kid as Cheese (Both small and cute)
 * Baby Mario as Chris (Both red and blue)
 * Wario as Shadow (Both Mario and Sonic's evil counterparts)
 * Daisy as Rouge (Both love to Luigi and Knuckles)
 * Donkey Kong as Vector (Both big and strong)
 * Funky Kong as Espio (Both quiet)
 * Diddy Kong as Charmy (Both small)
 * Candy Kong as Vanilla (Both love to Donkey Kong and Vector)
 * Mallow as Big (Both friendly)
 * Bowser as Dr. Eggman (Both the main villians)
 * Lemmy "Hip" Koopa as Decoe
 * Iggy "Hop" Koopa as Bocoe
 * Larry "Cheatsy" Koopa as Bokkun
 * Morton "Big Mouth" Koopa as Lucky
 * Baby Peach as Helen
 * Baby Luigi as Danny
 * Baby Daisy as Frances
 * Toadsworth as Chuck Thorndyke
 * Petey Piranha as Mr. Tanaka
 * Geno as Mr. Stewart
 * Smithy as Sam Speed
 * Flurrie as Ella
 * Tiny Kong as Tikal
 * Pewey Pirahna as Chaos 0
 * King K. Rool as Pachcamac
 * Bowser Jr. as E-102 Gamma

Version 2

 * Mario as Sonic
 * Oogtar as Chris
 * Yoshi as Tails
 * Luigi as Knuckles
 * Peach as Amy
 * Birdo as Cosmo
 * Rosalina as Cream
 * Polari as Cheese
 * Donkey Kong as Vector
 * Funky Kong as Espio
 * Diddy Kong as Charmy
 * Daisy as Rouge
 * Wario as Shadow
 * Petey Pirahna as Big
 * Bowser as Dr. Eggman
 * Lemmy "Hip" Koopa as Decoe
 * Iggy "Hop" Koopa as Bocoe
 * Larry "Cheatsy" Koopa as Bokkun
 * Morton "Big Mouth" Koopa as Lucky
 * Baby Peach as Helen
 * Baby Luigi as Danny
 * Baby Daisy as Frances
 * Toadsworth as Chuck Thorndyke
 * James Blonde as Mr. Tanaka
 * Detective Herlock Solmes as Mr. Stewart
 * Smithy as Sam Speed
 * Flurrie as Ella
 * Tiny Kong as Tikal
 * Pewey Pirahna as Chaos 0
 * King K. Rool as Pachcamac
 * Baby Yoshi as E-102 Gamma