If you liked the Pet Shop of Horrors manga, the Anime-Planet community thinks you'd like:
Mushi are another form of life which live parallel to our own natural world. The source of many myths and superstitions, they exist according to their own natural laws, and can be both beneficial and dangerous depending on circumstances. Ginko, a traveling mushishi, investigates and helps out wherever the mushi have become a problem. Yet Ginko himself is marked by the creatures he researches, and he carries the weight of his past with him.
Pet Shop of Horrors and Mushishi tell oft dark tales of the supernatural's influence on humans. I'd call Pet Shop closer to horror and Mushishi closer to something like Kino no Tabi (anime), but fans of one would DEFINITELY enjoy the other.
While Pet Shop of Horrors is darker in tone than Mushishi, both focus on the effects that the suernatural have on humans. If one of these interested you, then it's worth checking out the other.
'Pet Shop of Horrors' and 'Nightmare Inspector' are two series that feature a supernatural shop owner who is willing to help a client-- for a price. Both series are episodic, and also feature a combination of happy and tragic endings, depending on the client's desires and cooperation with their respective guide.
If you enjoyed reading 'Nightmare Inspector', you will definitely enjoy reading 'Pet Shop of Horrors', and vice-versa.
Nightmare Inspector: Yumekui Kenbun and Pet Shop of Horrors are simular manga. Both are mostly episodic and have supernatural feel to them. Both have mysterious and interesting main characters that run special shops. Most of the stories in both mangas contain some sort of moral lesson. Basically, if you like one then you will probably like the other.
Both mangas are supernatural-themed, and both divulge into what are mostly short stories. Unlike Pet Shop of Horrors, however, Beauitful People has no overall connection point and only was eighty pages long. However, if you were interested in the short stories in Pet Shop of Horrors, you'll probably like the ones in Beautiful People (and vice versa), as most of them follow similar themes.
All murdered souls arrive in limbo at the Gate of Grudges, where the Gatekeeper, Izuko, presents them with a choice: they may pass through the Gate into Heaven; they may cling to life on Earth and remain a ghost there forever; or, they may haunt and kill one person in exchange for eternal damnation. As each spirit passes before the Izuko she is bound to explain these options and impartially accept their decision; what will each choose? Peace, or spending an eternity in Hell?
Pet Shop of Horrors and Skyhigh may not seem similar at first, but both involve an (arguably, in PSoH's case) impartial person helping others make a choice. PSoH's characters almost always end up in a bad situation while Skyhigh's only part of the time, but they definitely have a similar feel.
At first glance, Kimihiro Watanuki appears to be a normal high school student; but little do people know that not only is Watanuki able to see spirits, but he's also a magnet for them! One day, after being chased by one such spirit, Watanuki happens upon a strange building. There he meets a mysterious witch named Yuuko, who claims she can get rid of his ability to see spirits - for a price: Watanuki must work as her housekeeper until he has paid off the cost of granting his wish. Now Watanuki's eyes are being opened to an entirely new side of the world as he assists Yuuko in her work, all while balancing the housework, his schoolwork, and most importantly, ensuring that Yuuko is never out of sake!
Both Pet Shop of Horrors and xxxHolic both feature episodic chapters with both supernatural and moralistic themes. Both look at the follies of mankind linked by supernatural punishment, though PSoH focuss on this more than Holic.