Nickelodeon/Sesame Street

Cast

 * Patrick (From SpongeBob) as Elmo (Both are cute)
 * SpongeBob (From SpongeBob) as Big Bird (They are both yellow and have high-pitched voices)
 * Tommy (From Rugrats) as Ernie
 * Squidward (From SpongeBob) as Bert
 * Carl (From Jimmy Neutron) as Cookie Monster (Their names both start with a "C")
 * and more