Here's some more ideas:
*Fozzie being heckled by Peter at a comedy club, and then Fozzie goes on a rampage and attacks him
*Peter has learned, "Never trust street bums" and it cuts to him on some inner-city street in NY and Oscar tricks him into buying something stupid. Of course, Peter falls for it.
*Swedish Chef rapping
*The crystal shard as a prop
*Have one ending of an episode spoof the usual endings of The Muppet Show-characters come out for the "goodnight"; Statler and Waldorf give last comment, and Zoot's saxophone
*(Insert character here) says that "people make many stupid mistakes all the time", and it cuts to Buffy the Vampire Slayer killing...The Count(!) Big Bird, Grover, Elmo, Ernie, Bert, Oscar and Cookie give her a devastated look, and later in the episode they show up at a graveyard and cry over his tombstone.
*Grover demonstrating "near" and "far"
*Oscar applies for a job
*Sesame Street ending spoof, with ALL the major classic characters seen in the background
*The reason why Sesame Street never really had a major female character, is finally explained: the male characters keep grossing them out everytime
*Racecars/spies cartoon spoof
*Someone uses Snuffy as his allibi (for doing something bad)
*Chris goes to war with the Fraggles after picking on him (of course Lois doesnt believe him, but we hear explosions, yelling, etc outside)
*Cookie Monster admits that he "did it all for the cookie"
*Lois is afraid to go outside the house again after being stalked by a bum/theif in the alley. When she attempts to go out, several things sartle her---Oscar comes out of a nearby garbage can. Lois runs off but he says "Hey! I just wanted to talk! (changes mood) Ah, forget it (drinks a bottle of alcohol) Nobody ever wants to talk to me (keeps on drinking)"
*A "big-nosed" criminal is out on the loose, who is described as "a man in blue". When it's on the news, they show an artist's depictual of what he might look like, and it's Gonzo. Later, the cops bust into Gonzo's home, where he's happpily relaxing in peace, and they arrest him. Gonzo tries to convince them that he's innocent.