For example:

Katy

OOTB - Hot n Cold
Teenage Dream - Firework
PRISM - Dark Horse

Now go!

Dangerously in Love: Crazy in Love (sales wise) / Baby Boy (chart performance wise).
B'Day: Irreplaceable.
I Am... Sasha Fierce: Single Ladies.
4: Love on Top.
BEYONCÉ: Drunk in Love.

Lady Gaga:

The Fame - Poker Face
The Fame Monster - Bad Romance
Born This Way - Born This Way
ARTPOP - Applause

Baby Boy
Irreplaceable
Single Ladies
BTINH
Drunk in Love

Im just guessing btw

MOTS:
Pon De Replay
AGLM:
S.O.S
GGGB:
Umbrella
Rated R:
Rude Boy
LOUD:
WMN
TTT:
WFL
UNA:
Stay (?)

DIL:
CIL
B'Day:
Irreplacable
IASF:
Single Ladies (?)
4:
.... Love on top?
BEYONCÉ:
DIL

Fixed

Animal: Tik Tok
Cannibal: We R Who We R (i feel like Blow is more used tho)
Warrior: Die Young
and then Timber if you count that as an era

Basically all her lead singles

#9. Rehab

..just goes to show that you don't need chart success to be legendary/iconic.

Thankful: Miss Independent
Breakaway: Since U Been Gone
My December: Never Again
All I Ever Wanted: My Life Would Suck Without You
Stronger: Stronger (What Doesn't Kill You)

Pink Friday - Super Bass
Roman Reloaded - Starships
The Re-Up - High School
The Pink Print - Pills N Potions

pon de replay
s.o.s
umbrella
rude boy
only girl
we found love
stay

The Fame : Poker Face.
The Fame Monster : Bad Romance.
Born This Way : Born This Way.
ARTPOP : Applause.

Anaconda is the bigger hit

Let Go: Complicated
Under My Skin: My Happy Ending
The Best Damn Thing: Girlfriend
Goodbye Lullaby: What the Hell
Avril Lavigne: Here’s To Never Growing Up

CTMH: Most Girls
M!SS: Get the party started
TT: Trouble
IND: U + Ur Hand
FUN: So What
GHSF: Raise Your Glass
TTAL: Just Give Me A Reason

Hard picking one for the 'I'm not dead' era. Though 'Who knew' failed to chart first and 'U + ur hand' was an instant hit from the start.

Brandy: Baby
Never Say Never: The Boy is Mine
Full Moon: What About Us?
Afrodisiac: Talk About Our Love
Human: Right Here(Departed)
Two Eleven: Put It Down

Love on Top is much bigger. Best Thing I Never Had just peaked four spots higher.

Meet Miley Cyrus / See You Again
Breakout / 7 Things
The Time of Our Lives (EP) / Party in the Usa
Can't Be Tamed / Can't Be Tamed
Bangerz / Wrecking Ball

Rihanna:

Music On The Sun - Pon De Replay
A Girl Like Me - SOS
Good Girl Gone Bad - Umbrella
Rated R - Rude Boy
Loud - Only Girl In The World
Talk That Talk - We Found Love
Unapologetic - Diamonds

Rih
Music of the Sun: Pon de Replay
A Girl Like Me: SOS
GGGB: Umbrella
Rated R: Rude Boy
Loud: Only Girl
TTT: We Found Love
Unapologetic: WW: Diamonds US: Stay