Really late reply considering the date of this thread, but I can't resist.
Ah, Kagome versus Kikyo. Who's the best woman for Inuyasha? That is an old argument I've seen across the length and breadth of this vast internet, and one I'll try to address for myself as best as I can.
1: Physical attributes. At first glance, they're both beautiful women in love with the same man, which makes you (or at least me) wonder about the lack of justice in this world. Kagome's got that popular sex appeal around her in the form of a Japanese schoolgirl uniform, stretched against her body in all the right places. That is of course her first clothing style. In later episodes Kagome wears a snug sweater and what appears to be a shorter skirt than her uniform allows, and this outfit identifies her as someone that wants to be *loved* and *loved well*.
Kikyo, despite having more than a passing hint of a seductive body buried underneath all her baggy clothing, is still covered under her baggy clothing. There simply isn't much on her you can look at that suggests *gimme some loving*, and she falls behind Kagome in that respect.
So you have to look at the faces. Kagome's young, and not only with those typical wide eyes. Her cheekbone structure suggests baby fat and growing muscles, which while being very cute, does not do it for me in terms of a mature woman conveying a hunt for fresh meat. So it's hard for me to take seriously any of the innuendo she occasionally says to Inuyasha or anyone else. Kikyo, on the other hand, has more of an angular chin and fully developed cheekbones, and that says to me "hey, she isn't jailbait." So despite covering her body in baggy clothing, Kikyo has the upper hand over Kagome in showing the audience that she's all grown up and ready to prowl.
Their foreheads are the same, their hairstyles differ but are colored the same. Kagome's eyes seem a bit bigger than natural for the size of her face. I think this is supposed to convey childlike innocence and hint at the woman she's growing up to be, which as I mentioned is plenty cute, possibly hinting at a sexy kind of cute. But Kikyo's eyes are drawn a little more narrowly and small, which fits her facial expressions perfectly, and this makes her incredibly ravishing when she frowns. God I wish she'd smile a little more often.
Heck, I'll write point number two a bit later.