Apparently K isn't a popular letter, I also didn't find many good ones in this list.

Kala’s Conditioning - Not sure why, but I didn't entirely like this story, perhaps because it's a nice/good person being abused instead of an asshole.  Still, parts are quite hot.
Karina - A very nice hot little story that reminds all us MCers to make certain the rules on adding new slave's be carefully explained and enforced.
Kari’s Awakening - Pretty straightforward, but has it's hot moments.
Karma Dog - This one was a lot of fun, I enjoyed it thoroughly as it's not your usual story.
Kat and Mouse - This falls into the messed up category, it's a story where MC gets a bit dark but the good do win in the end.  Well done.
Katie’s Promotion - Always make sure the subject of your MC potion take the WHOLE potion.
Katy Becomes A Whore - Predictable but quite fun
Keep Myself Awake - Evil little story, I think I'd have cut the arm off but something tells me that wouldn't solve the problem.
Keeping Up with the Joneses - If you EVER see this sort of thing start to happen.  MOVE immediately and as far away as possible.  The ending to this story was probably the best possible, I can imagine FAR worse.
Keeping Your Man Happy - Yes, keeping your man happy is VERY important
The Kidnap Show - Definitely has all the quality of a late night public access show(ok, QUITE a bit more than that).
Killing Me Softly - A very nice premise for a story, I enjoyed it.
The Kiss - Some hot and evil pet action.
Kiss and Tell - Short, but hot and a bit fun
Kitty Kat - A fairly fun cat transformation story.