Welcome to the world of Pokemon Visual Novels! Here I'll list some of the great titles available in English officially or by fan translation. For those new to the genre I'll have some picked out available for free as well as some titles available to purchase in English, but feel free to ask for some suggestions in the thread if you aren't sure where to start. These posts will be updated continually to add more to the roster, so PM me if you have one that I've missed!
Official Releases:

Availability: Out of Print
Developer: KID
Plaforms: PC
Rating: T for Teen
It is spring in the year 2017. Kuranari Takeshi, a normal college student, has come to visit the futuristic underwater theme park “LeMU” with his friends. However, an accident leads to a
breach in the upper levels of LeMU, and the theme park slowly begins to take on water. In the ensuing chaos, Takeshi suddenly finds himself trapped inside LeMU along with five other
strangers with no means of escape and no way to contact the outside world. With its structures compromised, LeMU will implode from the external pressure of the sea water within five days.
Takeshi and the others must now figure out a way to escape before it is too late.

Availability: Amazon
Developer: Chunsoft
Plaforms: Nintendo DS
Rating: M for Mature (Blood, Drug Reference, Strong Language, Suggestive Themes, Violence)
Junpei, a normal college student, suddenly finds himself along with eight other strangers involved in a deadly conspiracy he could never have imagined. He wakes aboard an old cruise liner.
Dazed and confused, he stumbles around the room he finds himself in, trying desperately to remember how he got there. The first thing he notices is a number, scrawled across the door…
A bright red number 5. As Junpei’s memory returns, his mind is filled with the image of a mysterious figure in a gas mask, and their haunting words:
“You are going to participate in a game. The Nonary Game. It is a game…where you will put your life on the line.”

Higurashi no Naku Koro ni/Higurashi When They Cry
Availability: Digital Download
Developer: 07th Expansion
Plaforms: PC, iOS
Rating: CERO D
Higurashi no Naku Koro ni takes place during June 1983, at a fictional rural village called Hinamizawa (雛見沢?) (based on the village of Shirakawa, Gifu, a World Heritage Site), which has a population of approximately 2,000. The main character, Keiichi Maebara, moves to Hinamizawa and befriends his new classmates Rena Ryugu, Mion Sonozaki, Rika Furude, and Satoko Houjou. Keiichi joins their after-school club activities, which consist mostly of card and board games (and punishment games for the loser, usually him.) Hinamizawa appears to be a normal, peaceful, rural village to Keiichi. However, the tranquility abruptly ends after the annual Watanagashi Festival, a celebration to commemorate and give thanks to the local god, Oyashiro. Keiichi learns that every year for the past four years, one person has been murdered and another has gone missing on the day of the Watanagashi Festival. Keiichi himself soon becomes drawn into the strange events surrounding the Watanagashi Festival and Oyashiro. In each story arc, he or one of his friends become paranoid, and a crime is committed. Usually, the crime involves the murder of one of their own friends. While it seems impossible to tell their delusions apart from the mystery of Hinamizawa, slowly the truth is revealed.

Availability: Digital Download (Free)
Developer: Stage-nana
Plaforms: PC
Rating: All Ages
The anonymous protagonist is diagnosed with a terminal illness shortly after his twentieth birthday, and is admitted to a hospital in Mito, Ibaraki. There he meets Setsumi, a woman a few years older, who is also terminally ill. Finding that they both reject to die either in hospital or at home, they steal a car and run away together.

Availability: ??? (Himeya undergoing restructuring recently so it is unclear.)
Developer: C's Ware
Plaforms: PC
Rating: 18+
A Bizarre Serial Murder Mystery. There's A Serial Killer Close By. A Prohibited Psychothriller. The Multi-Sight System Reveals Surprising Truth!
In this game there are two heroes, Kojiroh and Marina, who are each called to solve their own cases. This game allows you to switch characters at any time to solve the mysteries these heroes encounter. This 'Multi-Sight Adventure' allows you to view what's happening behind-the-scenes from the other character's perspective, bump into each other, and sometimes even help each other out. Together, they come closer and closer to the shocking truth through their combined actions and skills of deduction.
Marina's Episode: Marina is a national intelligence agent with a 99% success rate. Her new assignment is to protect the daughter of a Japanese embassy official stationed abroad. As you encounter numerous attackers, you become aware of a dangerous government dispute that is the root of all these attacks.
Kojiroh's Episode: A seemingly down-on-his-luck private investigator finally gets a break, as he is hired to locate some mysterious piece of art. Even though he feels a little weird about this case, the pay is huge! Yet he may be drawn into an unexpected nightmare involving a string of bizarre murders.

Availability: ???
Developer: C's Ware
Plaforms: PC
Rating: 18+
In the southern ocean on a remote island is a huge research institute called 'Desire'. An institute built by the large, world renowned financial group, Grandchester Foundation. It's rumored they are involved in military-related research, but what it is exactly is kept a carefully guarded secret. For this reason, a journalist for SNT (Social News Time Network), Albert Macdgul (or Al for short) visits 'Desire' in order to collect information for a story. He's one of the rare few who have been granted access to 'Desire'. So it's in high spirits that he sets forth to complete his story. While at 'Desire' he meets a girl named Tina, who is suffering from memory loss. She is destined to change his fate forever. Murder, bomb threats, mysteries shadowing her existence... How far will the chaos go? On the other hand, Makoto Izumi, technical manager at 'Desire', finds out how dangerous their research is, and asks her boss, Dr. Stella, to stop all the experiments. Then she finds out that someone on the outside is going to interfere with the research...

Availability: Out of Print
Developer: Abel Software
Plaforms: PC
Rating: 15+
The year 2000. Kasumi Shindo is at first glance a run-of-the-mill high school student in modern-day Japan. However, beneath his normal appearance, Kasumi is in fact a top-notch treasure hunter. This time, Kasumi is aiming to seek out the lost 11th Commandment of Moses. Kasumi discovers that his childhood friend, Reina Tachibana is in southern Europe participating in an archeological dig. Pretending to be a tourist, he visits the excavation area and manages to get put on the excavation staff. But he is not the only treasure hunter looking for the Eleventh Commandment of Moses and before he knows it, he's embroiled in a dangerous adventure.

Yume Miru Kusuri - A Drug That Makes You Dream
Availability: Digital Download, Online Order
Developer: Ruf
Plaforms: PC
Rating: 18+
Kouhei Kagami is a Japanese student with excellent grades and a fairly normal social life, but feels empty and transparent inside. The story revolves a pivotal moment in Kouhei's life where three girls more depressed and lonely than himself get involved with him and make his boring life a roller coaster of emotions. Kouhei must choose one of them or risk losing all of them to their own despair.

Kira Kira
Availability: Digital Download
Developer: OverDrive
Plaforms: PC, iOS
Rating: 18+ and All Ages
Shikanosuke Maejima is a student at the Missionary school, Oubi Academy. He doesn't attend his club, he doesn't put much effort in his studies, all he does is show up at his part time job; in short, his life could be better. One day, he meets a strange girl, Kirari Shiino, at work and before he knows it, they've formed a punk band.
Kira Kira Curtain Call
Availability: Digital Download
Developer: OverDrive
Plaforms: PC
Rating: 18+
Several years have passed since the amateur band Second Literature Club spent a summer touring Japan and performing live. When Shikanosuke and his friends graduated from Oubi Academy, the legends they left behind drew several experienced musicians to seek entry into Oubi Academy. Every year, these excellent musicians seek to join the Girls Light Music Club, which inherited the name of Shikanosuke's band, and every year they give high quality performances rivaling the original.

My Girlfiend is the President!
Availability: 2011 Release
Developer: Alcot
Plaforms: PC
Rating: 18+
It started out as an ordinary morning, woken up by my childhood friend. Had a good breakfast… complete with morning hard-ons. An ordinary, everyday eroge scene. Or… so it seemed. Things would never be the same from that day, as peaceful everyday life was blown to bits. An accident on a spaceship heading to earth, causes it to crash on the Prime Minister of Nippon’s office. The leaders end up in a state too horrible to see. To avoid chaos, the lo-[censored] alien choose a girl who happened to be there, and to make ends meet, brainwashed all of mankind. Nippon adopts a presidential system overnight, and incredibly, a girl, my childhood friend, is the president. The world will answer to her every whim. And not a soul questions this strange world.
The president of the major power Russia, comes to Nippon. The dangerous Tsar of beautiful Russia. And a spaceship comes to attack. An international crisis breaks out over the hero. What will happen to the world? Why did this happen? The hero somehow remembers how the world was til yesterday. Based on his memory, the world is put back together again.

Deus Machina Demonbane
Availability: Release Candidate in testing.
Developer: Nitro+
Plaforms: PC
Rating: 18+
Arkham city is a bustling hub of commerce and industry, however Arkham is also a center of eldrich lore: home to Miskatonic University, an institution of higher learning with one of the most complete libraries of arcane literature in the world. In the span of two generations the town was built up to the status of prestige it now commands, an expansion helmed by the Hadou Group, an industrial complex and family dynasty currently run by the young Hadou Ruri. She pursues the peace and prosperity of Arkham diligently, against the forces of darkness threatening to plunge the city, and the world, back into a second dark age. Among the most sinister threats to Arkham City is the evil Black Lodge syndicate. Led by the charismatic Master Therion, his nihilistic outlook shapes the group's destructive goals: with a circle of powerful sorcerers at his command, the potential for sowing chaos in the city is unmatched.
Former Miskatonic University Magic Academy student Daijuuji Kurou knows little of grimoires, but what he does know terrifies him - enough that he left his university life behind, and now practices a failing detective business in the shelter of an orphanage in a quiet corner of Arkham. But just when he thought his Academy past was buried, it catches up with him and pulls him back into the dark shadows of the occult: Hadou Ruri herself appears at his door with an offer he can't refuse. The only way to combat the Black Lodge's growing magical power is to find, and retrieve, a grimoire with the power to activate the mightiest Machina of all: Demonbane. The quest to find this forbidden tome will change Kurou's destiny... forever.

Availability: Out of Print
Developer: Konami
Plaforms: Mega-CD
Rating: T for Teen
On June 6, 1996 (1991 in the Japanese versions), a chemical weapon known as Lucifer-Alpha under development in Chernoton, Russia, is released into the atmosphere, resulting in the death of 80% of the Eurasian population which in turn results in the death of half of the world's population. The contaminated area becomes uninhabitable for a decade, when Lucifer-Alpha mutates into a non-lethal form. This tragic event later becomes known as 'the Catastrophe'.
Fifty years later, a breed of artificial life-forms or bioroids known as 'snatchers' began appearing in the artificial island of Neo Kobe City, killing their victims and taking their place in society. Nobody knows exactly what they are or where they come from. As Gillian Seed, an amnesiac working for an Anti-Snatcher task force called J.U.N.K.E.R., the player's goal is to track down the source of the snatchers and discover Gillian's mysterious connections with them.

Availability: Out of Print
Developer: Nitro+
Plaforms: PC
Rating: 18+
Phantom of Inferno is a story detailing the life of a 15-year-old Japanese boy who is kidnapped after witnessing the killing of a reporter. After being kidnapped his memories of his past life are erased and is given the choice to join Inferno or die. He makes the only choice he can to join and is given the name Zwei and will study under Ein. She is also known as Phantom since this is the title given to the organization's top assassin.

Availability: Available Now
Developer: Cing
Plaforms: Nintendo DS
Rating: T for Teen
The main setting is the fictional Hotel Dusk, a small, somewhat rundown hotel located in the southwestern United States near Los Angeles, California during the year 1979. The protagonist is Kyle Hyde, a former member of the New York Police Department searching for his old partner, Brian Bradley. During his stay at the hotel, Kyle unravels a mystery shrouded in the hotel's past that may lead him to the answers he's looking for.

Availability: Digital Download
Developer: Child-Dream
Plaforms: iOS
Rating: N/A
A Scar of the Doll is a psychological horror visual novel with adventure game elements, directed and written by Folklore scenario writer Hidehisa Miyashita. The story is set in late December and revolves around the young woman Asumi Kamijo. She has lost all contact to her older sister, who goes to a graduate school in Tokyo. Worried about her, Asumi travels alone to the capital to confirm her well-being, but the lab she was assigned to and the apartment she lived in show no trace of her. Asumi is determined to find out what happened to her sister, though she does not know the horrors that await her in the midst of uncovering the truth.