Oh my, such a marvelous question!
Though there were many that whetted my appetite for the Sesshoumaru/Kagome pairing, but there are really 4 stories that share the blame for my addiction
(Please keep in mind that all of these stories have adult themes and either toe the line of or completely cross over into MA ratings, so please read responsibly):
(R) A Question About Honor by KogasAngel
A Question About Honor EDIT BY WICCAN: This story is rated MA on our site, NO YIMs!
(NC-17) A Sentinel Mother by Demonlordlover2
A Sentinel Mother
(R) Convivial by The Hatter Theory
Convivial (I don't remember this actually crossing the line over into NC-17, but there may be some hard-R scenes)
EDIT BY WICCAN: This story is rated M on our site, NO YIMs!
(R-ish?) Lord Charming by Forthright
Lord Charming (this story stays in the hard PG-13 to light R for most of the series, until the last chapter, so read carefully)
EDIT BY WICCAN: This story would be rated M on our site, NO YIMs!
As you can see, I do love a slow burn and Frenemies to Love stories!