One of my favourite less-popular (maybe?) TBK characters is Katerina Ivanovna. Not only because of the ship (tho in some way it is because of the ship), but also because she's deeply flawed, but after all her heart is set out for good, and somehow I really relate to her (which I suppose says a lot on my part).
She wants so badly to be 'good' and to do the morally 'right' thing (i.e. sticking with Mitya) and yet always seems to mess up. She has normal intentions but carry them out very misguidedly (the scene with Grushenka). At the same time she can also be very kind-hearted (giving that money to Captain Snegiryov), though that can be attributed to her want for martyrdom, but only in part I think. She actively offers to make amends and help Mitya escape after the whole court drama, and also withheld from questioning him about all that money he lost.
And she sacrificed so much of her own reputation by 1) making it look as though she came up with the idea to prostitute herself for the money during the trial instead of making Mitya look bad 2) and then proceeding to defend Ivan which would inevitably cause gossip and 3) keeping Ivan at her house so that he can recover, which supposedly should be considered very improper at the time. There's also the small detail that she paid for Ilyusha's funeral. Of course, a lot of all these good deeds could be attributed to personal reasons and her pride and whatnot, but I refuse to believe that it's the sole reason!
And then there's this quote:
“Love is gone, Mitya!” Katya began again, “but what is gone is painfully dear to me. Know that, for all eternity. But now, for one minute, let it be as it might have been,” she prattled with a twisted smile, again looking joyfully into his eyes. “You now love another, I love another, but still I shall love you eternally, and you me, did you know that? Love me, do you hear, love me all your life!” she exclaimed with some sort of almost threatening tremor in her voice.
And I'm sure she tormented herself so much after the trial ordeal. Like she probably thinks she's the worse person in the world after that, and probably cried for too long, and
In short, I love my deeply flawed, constantly messing up, but also very kind girl. Just a proud young society lady who so desperately wants to do everything right.