beyonce. her hits go back to her destiny's child days. bootylicious is in the dictionary for christs sake
rihanna has hits but she hasnt been here slaying for over a decade like beyonce has. beyonce is a vet in the game so naturally she would be the one with more hits

Beyonces date back to the late 90's, the comparison is unfair to begin with.

No No No
Bills Bills Bills
Say My Name
Bootylicious
Survivor
Independent Women
Crazy In Love
Dangerously In Love
Irreplaceable
Listen
If I Were A Boy
Single Ladies
Halo
At Last

Definitely Rihanna.

Rihanna

Beyoncé.

Counting Destiny's Child, Beyoncé.

Rihanna.

Rihanna

Beyonce. Rihanna really only has 2 smashes in the US (WFL & Umbrella), whereas Beyonce has 3.

In terms of Signature song, Beyonce has two that you can argue between (Single Ladies & CIL), whereas Rihanna really only has one clear choice (Umbrella).

Rihanna.

+1.
Also even though Rihanna may technically have more #1s and successful hits the only "signature" hits Rihanna actually has are probably WFL, Umbrella , Dont Stop The Music and Disturbia. Maybe Whats My Name and Pon De Replay but thats slightly reaching. Sorry Navy.

Beyonce. Rihanna has more hits, but most of them aren't "signature."
No one cares about Pon De Replay, Unfaithful, Hard, Russian Roulette, Cheers, Shut Up and Drive, etc.