10 Greatest Celebrity Guest<br />Spots on 'The Simpsons'.<br />With a total of 672 episodes, ‘The Simpsons’ is the<br />longest-running American sitcom and longest-running<br />scripted primetime television series in TV history. .<br />In honor of the animated comedy<br />celebrating its 30th anniversary,<br />here are the show’s 10 greatest<br />celebrity guest spots.<br />1. Danny Devito (Herb Powell).<br />2. Willem Dafoe (The<br />Commandant & Jack Lassen).<br />3. Stephen Colbert (Colby).<br />4. Mark Hamill.<br />5. Jeff Goldblum<br />(MacArthur Parker).<br />6. Alex Trebek.<br />7. Buzz Aldrin.<br />8. Johnny Cash<br />(Homer’s Spirit Coyote).<br />9. Michael Jackson<br />(Leon Kompowski).<br />10. Meryl Streep (Jessica Lovejoy)
