Cloud Palette
Tokoharu
GP-KIDS
Yuri Landim + Amanda Landim <- They work in combo
Mekimeki Oukoku

Just noticed... None of my top fav mangakas do original works...

Yohane, nobody does that "girl deeply in love" face better.

Millet Soup
Tanaka Minorou
Aki Eda
Pikachi
Sagamani
Kohagura
Chi-Ran
Morishima Akiko (although she does a lot of series stuff too)

Of course I love the ones already mentioned too.

Vivit Gray and Takemiya Jin

at the moment, Nishi Uko. I am fangirling so hard that I get waaaay to excited when new one-shots of hers are released.

Vivit Gray and Takemiya Jin

Oh man, how could I forget Takemiya Jin? She might actually be my absolute favorite.

And yeah, Nishi Uko is fantastic too.

I dunno, I see Takemiya Jin as more of a series artist, generally speaking. Or at the very least interconnected short stories rather than self-contained one-shots. But I guess you could call it either way, just whatever your personal perception is.