Blackout is a better album but I agree with you about In The Zone, "Toxic" is still Britney's best music video to date.

Lady Gaga, the monster era.

The Killers - Sam's Town era
Shakira - Laundry Service era
Black Eyed Peas - Monkey Business era
Beyoncé - I Am... Sasha Fierce era

ray of light
the fame monster at the end of 2009

You better preach. YAS!

Three Days Grace - One X era (that one was easy )
Shinedown - Arghhh this is hard. I love each era equally. >.< I can't choose one.
Apocalyptica - Worlds Collide era (when their symphonies were a little harder )
Evanescence - The Fallen era
Daughtry - Self Titled album era. They were more rocky. Now they're all pop. >.<
And for the hell of it:
Kelly Clarkson - My December era (Never Again/Sober = <3)
Pink - I'm Not Dead
Nickelback - Silverside Up era (How You Remind Me, Too Bad, Never Again etc)
Yeah. lol

Legend.

3 worldwide #1s
10 million+ sold
Grammy winning first single "Toxic"
co-wrote 8 out of the 12 twelve tracks

plus it was an unfinished masterpiece after the promotion was cut short after her fall

Britney - ITZ
Christina Aguilera - B2B
Taylor Swift - Speak Now
Scissor Sisters - Ta-Dah!
P!nk - Funhouse
Demi Lovato - Here We Go Again

Bey-B'day
Rih-GGGB
Mariah-Butterfly
Aaliyah-Aaliyah
Alicia Keys-The Diary of Alicia Keys

Hands down the best album of the last decade

shes not exactly a favourite but Mariah showed them gorls how to do an era with The Emancipation


biggest comeback of all time

Truth of the world

good girl gone bad


These albums got them to the top 3 or number 1

From Cobra Starship--The Hot Mess Era
From Britney--The Blackout Era
From Gaga--The Fame Monster Era
From Rihanna--The Rated R Era
From Ashley Tisdale--I liked the Guilty Pleasure album more but I enjoyed both eras as a fan. I'd probably say that in the end I guess I favor the GP Era a little bit more though

The Fame
Blackout
B'Day

Britney - "In The Zone"
Ke$ha - Well, so far, "Animal" but expecting the "Cannibal" era.

Paramore - "Riot!"