In which album is 3 by Britney Spears?

...Baby One More Time (1999)

Oops!...I Did It Again (2000)

Britney (2001)

In The Zone (2003)

Greatest Hits: My Prerogative (2004)

B in the Mix: The Remixes (2005)

Original Doll (Never released) (2006)

Blackout (2007)

Circus (2008)

Britney Spears: The Singles Collection (2009)

And another one is coming in 2010.