When Meg does her bird calls, BIG BIRD from SEASAME STREET shows up and chews her out.
There's another Family Guy one that people forgot. Peter's watching a show called Homicide:Life On Sesame Street. It has Ernie and Bert. The phone rings. Bert Answers.
BERT:Hello? Son of a *****.
ERNIE:Bert. What's the matter, Bert?
BERT:Some poor ******* got his head blown off at a place called Hoopers.
(Bert takes a swig of something)
ERNIE:Bert. I wish you wouldn't drink so much Bert.
BERT:I wish you'd stop eating cookies in the **** bed.
ERNIE:Bert. You're yelling again Bert.
and Peter is Beaker , are the only ones. The Simpsons have the majority of Muppet/Seasame Strret refreances