Number of years Cats ran on Broadway:

21
Retired on its 21 birthday
Source: , 1/1/1900

 
   
  Worlds longest running musical:

Les Miserables

Source: , 1/1/1900

 
   
  Best movie musical, according to the American Film Institute:

Singin' in the Rain
"Singin' in the Rain" topped the AFI's "25 Greatest Movie Musicals" list, followed by, in descending order, "West Side Story," "The Wizard of Oz," "The Sound of Music" and "Cabaret."
Source: CNN.com, 9/5/2006

 
   
  Nude musical that Milwaukee police shut down in August 2005:

"Naked Boys Singing"
Police claimed they closed the show on August 18th, 2005, because the Milwaukee Gay Arts Center didn't have a theatre license. The show was also closed by police in Atlanta, San Juan and (of all places) Provincetown, Mass.
Source: Milwaukee Journal-Sentinel, 9/8/2005