I got an urge to reread BIBLIOMANIA.
It's a short (12 chapters), creepy story about a girl named Alice stuck in an empty room. It has supernatural horror and post-apocalypse elements as well as some really cool, imaginative and freaky art. One of my favorites.
As for ongoing series, two I follow updated this week:
Both really funny and cute stories, definitely worth a check if you didn't hear about them.
Apparently Kono Healer, Mendokusai also updated few hours ago, so that too.