S2: Four Kings - Bison, Vega, Sagat, Balrog
S3: 3S/USF4 - Dudley, Urien, C. Viper, Alex
S3: ST/USF4: Fei Long, Gouken, T. Hawk, Hakan
There are a million characters I want back, honestly. Hopefully the final version of the game has at least 40 characters, they are too many great ones to leave behind. Especially because the core game plays great so I want to say these older characters in the new system.