Sure. The Ouran Host Club manga has finished. It had a proper conclusion that covered all the important aspects and left a lasting impression on readers.
There's also 'Magic in the Host Club'. In this one, the OC is a magician who accidentally stumbles into the club. The story is full of fun magic tricks and how the OC uses her skills to charm the members of the club. It's a really light - hearted and enjoyable read.
The fanfiction 'With Honey by My Side' is also worth checking out. It shows the OC and Honey going through various school events together. The author does an excellent job of creating a believable relationship between the two within the world of Ouran Highschool.
The Ouran High School Host Club manga is indeed complete. It wrapped up with all the storylines resolved and characters' arcs concluded. Fans got a satisfying finish.