Ugh, hard question.
I wouldn't delete any of them tbh since they all helped her learn from her successes (Pink Friday + TPP) and mistakes (Roman Reloaded)

But probably RR, since it adds the least value (musically) & it only helped her achieve global status

Any of Rih's first two albums a.k.a "mixtapes". Probably MOTS

Since I don't consider 'LDR AKA Lizzy' as part of Lana's discography but from Lizzy's so I'll delete Ultraviolence
This was VERY hard.

For Gaga, I'd delete AP. I can live without that one even if it had a few bops.
Same for Kylie Minogue's Let's Get To It.

True Romance>> Sucker, so I'd delete Sucker by Charli XCX.

Taylor's debut.