The Thundermans/Sonic

Version 1:
Billy as Sonic (Both are fast)

Max as Knuckles

Hank as Vector

Barb as Blaze (Both start with B)

Phoebe as Tails

Cherry as Amy Rose

Dr. Colosso as Dr. Eggman (Both start with Dr.)

Cream as Nora

Version 2:
Hank as Sonic

Barb as Sally

Max as Dr. Robotnik

Phoebe as Blaze

Cherry as Amy Rose

Cream as Nora