Homer's sister just happens to be the best of the bunch at the moment (in my opinion, of course, though that shouldn't have to be stated). I've never been a huge fan of the Darcsen designs past Wavy. They just look bland and uninteresting to me, and the first game went so far into drilling the idea that "Darcsens are all saints" despite the intended message that you shouldn't judge people based on race (which should mean good OR bad, and by making all of the Darcsen borderline immaculate they kind of killed that) that I got a bit fed up with them. I'm actually glad 3 is addressing that with some Darcsen enemies, and I hope they don't subvert that in some way and end up making them "good guys" in the end.
As for the Valkyria girl in this one, I can't look at her without thinking of him -
http://www.freewebs.com/lmcat/tails.gif
Even beyond that though, and despite always being the first to admit having a raging redhead fetish, I like my women cheerful and happy, not dark and brooding. That kicks Imuka out for sure, and from what little we've seen (granted, not much at all) the Valkyrur (though she's been shown smiling in some shots, IIRC). I want Cherry, Ramona, and Freesia, not tall, dark, and angsty. Again though, we'll have to wait until we know more about the characters for that - I'm just basing off of first impressions.
God I hope Cherry is DLC in this one...