The decade only consists of 10 years, and it was actually 2000-2009. Anything that happened in 1999 or 2010 didn't count towards that decade. At least not charting purposes. For Britney eras that leaves...

Oops.. (2000)
Britney (2001)
In The Zone (2003)
GH: My Prerogative (2004)
Blackout (2008)
Circus (Dec. 2009) - most of this era wouldn't even count as that decade...

For Beyonce we have

Dangerously in Love (2003)
B'Day (2006)
I Am...Sasha Fierce (2008)

but keep in mind, Beyonce DID have impact with Destiny's Child. Their eras in the last decade were..

Survivor (2001)
Destiny Fullfilled (2004)
#1's (2005)

I think people have a hard time saying Britney because after 2004, her impact died down tremendously. Thats half the decade. Beyonce on the other hand owned throughout the whole decade. So I feel like she wins this.

Jennifer Lopez should be here.

In the 2000s:

Britney- 59 million albums
Beyonce + DC- 54 million albums

/endthread

I think Beyoncé in the US and Britney WW.

The legendary Miss Britney Spears

I agree.

Shakira.

Britney Spears. The Queen of all recorded music. The one that sold 60 million albums in the 00s decade.

Only the Queen Of Colombia/USA.

And all by herself

Beyonce.

Gaga has outsold every single Beyoncé album since her debut.

My Prerogative was bigger than any 2000 Beyoncé single.

Beyonce.

Anyone saying Gaga is deluded. She became popular in like 2008. There's no way she made more of an impact in that year and 2009 than the rest did in the whole decade

My answers are Britney and P!nk.

Bey, Brit or P!nk.

In pop culture, Britney. In music, Pink.