I have nothing against Nikki tbh, I just don't like her path. Blueballing, hanging in her room, cumming on canvas etc. not my cup of tea. I also find Yuki and Carol paths boring. I do love Rachel path, though I don't know how it will unfold so I am skeptical about her. Though, I must admit her path as interesting as Roxy's. Actually, they are similar in a way. In Roxy path MC tries to bring out her sweet part, in Rachel path MC tries to bring out her wild side. Similar paths, opposite directions.
Anyways, my favourites are Roxy(with huge margin, I like her and her path more than all other LIs combined), Rachel, Sara, Ashley, Kim and Lexi. I don't like Carol, Yuki, Natalie, Mallory and Nikki paths. I am not sure about Sasha and Abby paths, I need to see more to comment on it.