I should start by saying this isn't her best album. Clearly. It doesn't have that shock value that her previous albums had (Even FF for me). That doesn't mean it's bad though. I think it's lacking a super standout. I pretty much like all the songs the same, except for "It Should Be Easy"... i really hate that one. Overproduced mess.
"Don't Cry" was the surprise for me. It's like a mix of Blur and I Run Away. I love her vocals and the melody.
My top 3 are definitely Work Bitch, Passenger and Don't Cry. I like Alien, 'Till It's Gone, Perfume, Tik Tik Boom and Body Ache pretty much the same. Chillin W' U is a mess, but I love it. I admit it's a mess though.
It's too soon to rank this amongst all her albums but if I had to do it i'd say:
Britney=In The Zone>Circus>Femme Fatale>Britney Jean=OIDIA>
Also, the album is a grower. Like i said, it doesn't have the shock value but I haven't stop playing it since it came out and I love it more and more with each play