All right, enough with the slacking!
Ghost Hunt
Young teenage girl Mai likes telling ghost stories with her friends. Someday a supernatural investigation is launched at her high school, and after a mishap where the assistant investigator is injured, she finds herself replacing him in helping 17 year old head investigator Naru (short for Narcissist, due to his charming and remarkably humble personality, nicknamed by Mai and everyone followed up through on that ^_^) in this investigation an later on taking on a part time job officially at the Shibuya Psychic Research Center.
Adapted from a series of light novels by Fuyumi Ono (aka the writer of 12 Kingdoms), Ghost Hunt is made by a series of a few episodes long case stories. The cases are pretty classical haunting and ESP based stories, and never very surprising, but all very solidly told in terms of pacing, atmosphere and storytelling and as a result very successfully enjoyable and entertainingly creepy, each one better than the previous one. They also manage well to be credibly build their world in a way that made me want to reach for my Second Sights book to play nWoD: Ghost Hunters, if you see what I mean.
There's also a definite appeal to the cast dynamics. Naru is a pretty amusing character - a rather antisocial, extremely intelligent, exigent and dry-witted young man - and he plays up to Mai - your ordinary cheerful high school girl with a spine and lots of natural curiosity - in a very entertaining way. The secondary characters - we've got a kind hearted Australian Catholic priest, a laid-back and fashionable Buddhist monk, a Shinto priestess with a bad temper, a famous Medium girl with a traditional demeanour; and Naru's protective and laconic assistant - also all have their appeal and their moment to shine.
Although it's not show where i can point out one thing and say : "this is why it's awesome", I really enjoyed watching it all the way through, it's just
solid and well done overall. The animation is also excellent and very fluid, and the musical atmosphere quite good.
One of the only bad point i have against it is that the series ended short of adapting one of the key reveal from the light novel, which I had to go find out on the internet (there's manga adaptation which does go until there, for the curious) - and it's a shame because that's one reveal that made me even more interest in the characters and their relationship.
Ghost Hound
In a small village, eleven years go, Taro and his older sister were kidnapped and imprisoned in the disaffected hospital beneath the dam, and when their kidnapper died unexpectedly when he was chased by the police, it was three days before they were found. Taro's sister was dead then. Nowadays he's a 14 years old boy whose whole family is still trying to get over the trauma of what happened. When a new boy from Tokyo, Masayuki, who likes asking uncomfortable questions spurs Taro and another boyfrom the village, Makoto, whose father may have been involved in the kidnapping before killing himself; to go back together to the deserted hospital in an effort to exorcise their fear and the mysteries from the past, they all end up having an Out of Body Experience, opening up to the Unseen World.
All right, as you see it's not exactly a simple premises, it's got a lot of texture, a lot of interesting and intriguing details interwoven thematically. The pacing is pretty slow, but it's got gripping atmosphere served by some of the most creepy sound effect I've ever seen. The characters are all very well realised and compelling. They play onto your average anime archetypes, yet feel much more realistic (and flawed) than that, while still ending up making you feel concerned with them. The somewhat claustrophobic setting in a small village where everyone knows everyone also works great.
In terms of the main mystery, I found the end of the story a bit of a disappointment, with a rather anticlimactic ending which didn't end up solving as much as I hoped it would. In fact, the true emotional climax of the story is three episodes before the actual ending, playing up to the psychological and character development which was the true highlight of the story. Despite the disappointment in the overall story, it's still got some really effective ideas, mixing psychological, quantum physic, biological and mythological concepts from right and left and building up a fascinating tension, interweaving characters and thematics in a great way.
The animation and graphics are top notch, and a pleasure to see. I love how they designed the Unseen World, full of old extinct species done with very lovely CGI. I really love the OP, too.

The main characters from Ghost Hound : sweet and cute Taro, nosy and cocky Masayuki, troubled boy with an attitude Makoto, and Miyako, a sensible elementary school girl and daughter of the local Shinto priest who sometimes gets possessed.
(so yes, I did review the two Horror anime with very similar names together on purpose ^_^)