Falco's head in a jar must sing, or else! Fortunately, since Futurama is full of late 20th century references, and the Simpsons have refered to Falco numerous times (from "Help Me Dr. Zaius" to "Thank you, Taco, for that lovely tribute to Falco"
, there's a good chance we will get to see this, and I won't have to destroy the world.
Phil Hartman's voice would of course be handled by Billy West. I think they could make it tasteful yet funny (just watch the first episode of season 5 of News Radio to see how it's done).
I'd also love to see:
* Mr. T
* Devo's heads in jars (wearing their "energy dome" hats on the jars, with Alan and David fighting over one)
* Rupert Murdoch and News Radio's Jimmy James (not Stephen Root, the actor; Jimmy James, the character)
* David X. Cohen, together with whoever registered with the name David Cohen before him (assuming the X is because of guild rules)
* Alf
* the cast of Friends, with Marcel the monkey somehow still alive and screwing with David Schwimmer's jar
* the "not so great" Presidents at the end of the hall--from Grant to Harrison to George W. Bush
* the hall of Soviet leaders (but they may have to skip Andropov, because I don't remember them ever admitting that he died), mainly because I want to see how Kruschev bangs his shoe on the table
* Eminem--with a contest to pick your favorite of three new colors for him
* Michael Jackson, plus Michael Jackson's original face in its own jar
* Tracey Ullman
* Scooter
* Corey Feldman and Corey Haim, mislabeled (and Fry asks them "Which one of you sang "I Wear My Sunglasses at Night?"