A Dog’s Life - A very good dog transformation story, I think I read it years ago.  I still like it.
Doing the Stepdaughter - Simple straightforward, sexy
Doing Your Homework - Not long, not complicated, but quite hot and loved the last line.
Dollars and Sins - Quite deviant, but very hot I read this when it was originally posted and it's still good.
Donna’s Delight - Definitely incomplete, but still quite good and very hot.
The Doodad - I enjoyed this story, it could use more parts but they aren't needed and it was a lot of fun. 
Doorway (Flem the Raven) - When casting spells, it is best you do them on a person or make sure that they're one time use.  Doorway spells can be especially insidious but I think she actually got what she wanted.
Downsizing Lisa - Great story, it would have been nicer if his rival were shown to be a bit more of a bitch on heels but her slow transformation from Lawyer to slave is very well done.
Dr. Fox and the Trouble with Trent - Fun story, loved the twist near the end.
Dr. Fox and Wendy Warden’s Wrist - I definitely like the way the author things, also quite hot.
Dramatic Saga of Peter Q. Kleeshay - Nerd discovers hypno liquid enslaves family, grows harem.  simple but fun(fairly long)
Drawing From Life - A very nice story with hot parts and an actual plot.
Dream - Nice, simply, VERY erotic
Dream a Little Dream With Me - I am SHOCKED that nobody on MCStories has this as one of their favorites.  The struggle the main character goes through is great!  I'd recommend the author but this is his only work.
Dream State - Beautiful and well written if a touch Long(165K words) I believe I've enjoyed every story JiMC has written.  All 3 of them. 
The Duel (The Persuader) - Gotta love a MC story where the one being controlled is the on that believes they are in control.  Nicely done.
Dumber Switch - Simple, but quite enjoyable on the lines of device changes women genre.
Dungeon of Reality - and this is why we should be VERY careful when full dive VR becomes a reality.  I plan to write MANY many games for it myself.
Dying to Live - This is another good story that I'm surprised nobody has favorited.  There's some dark stuff in it but the hero is basically a good guy :)