Stripped is her magnum opus, so I'd go for that one. And it has a lot of Mariah-esque moments (Loving Me 4 Me, Impossible, Walk Away), so you'll probably enjoy it.
B2B is also top notch but too many fillers and too long overall. But if you like Stripped, you should check it out and skip the unecessary interludes (and some of the corny uptempos on disc 1)
The debut is cute, but Lotus is like the continuation of it, so if you didn't love Lotus, it'll be a waste of time I think
Emancipation needs to lose at least 2 tracks in the next update, preferrably Mine Again and Shake It Off, although the latter won't happen since it was a hit.