Purely based on vocals, i think justin was best showcased on the 20/20 experience even though its not his best album.
Bruno sounded amazing throughout unorthadox jukebox.
P!nk sounds best to me on try this (despite the flopping)
Florence sounds slightly better to me on lungs than on ceremonials
Marina sounds best on the american jewels ep
Ellie sounds like an angel on lights
A lot of these aren't even my favorite albums from their artist which i thought was kind of interesting.
Mariah - Emotions
Whitney - The Preacher's Wife or the Bodyguard? Hard to say because her live performances make her studio recordings seem weak in comparison.
Janet - Rhythm Nation
Bey - 4
(out of the two)