To be into anime is to at some point watch a series that's based off a light novel, novels typically aimed at young adults in Japan. In the same way that Hollywood pulls from comics and novels (and old films) for their films today, anime pulls from manga and light novels. This has especially been true in the last two decades, as the popularity of certain light novel adaptations has led to studios rushing to grab any remaining series in the hopes of stumbling on the next major hit. For this list, we'll be focusing on some of the biggest and best anime based on light novels, not only for their overall quality, but their popularity and impact on the genre.
10 GOBLIN SLAYER
Goblin Slayer has its share of haters due to some of its…controversial earlier moments. Having said that, there’s no denying it’s absurd popularity, as it became the most watched anime during the season it aired. A large part of that comes down to its’ simplistic, but familiar high fantasy roots that feels reminiscent of countless games of Pen and Paper RPGs.
The other half of it is its likable protagonist: a stoic man only stirred to action for the cause of slaying goblins, he’s easy to relate to as a character that’s great at one thing but pretty terrible at everything else.
9 NO GAME NO LIFE
Before the isekai genre became completely oversaturated but after everyone realized it wasn’t going away anytime soon, No Game No Life hit the airwaves in 2014. It featured Sora and Shino, an agoraphobic brother-sister duo who exist in the gaming world as Blank, an undefeated being. When the two defeat the gaming god Tet, they’re transported to an alternate world known as Disboard, where all conflict is solved with types of games. But No Game No Life’s story takes a backseat to its enigmatic lead characters and breathtaking world brought to life by Madhouse. Over half a decade later, fans are still begging to see more of this series.
8 GRIMGAR OF FANTASY AND ASH
By the time Grimgar hit the scene, the isekai genre was already packed with tons of characters being sent to other worlds and becoming incredibly overpowered. Grimgar manages to turn these expected tropes onto their heads, by focusing on a group of young teenagers who…weren’t powerful at all. The series saw them struggling against low-level monsters and just trying to make enough money to buy clothes and food. It saw them try to figure out the mystery of how they got to this new world, and their changing emotions while dealing with puberty. The series manages to carve its place in the isekai world by perfectly mixing RPG fantasy with coming of age tropes.
7 SWORD ART ONLINE
This series is almost a requirement to be on this list. It started out by doing the unlikely and being one of the few light novel adaptations that isn’t immediately canceled after its first season. Instead, it’s been chugging along pretty steadily since it first aired in 2012.
Plus for better or for worse, Sword Art Online transformed the anime industry by making the isekai sub-genre a major one for the industry. Though they existed before the series came along, it wasn’t until Sword Art that a proliferation began — this season alone there are four isekai anime airing, and they all owe it to Sword Art’s popularity.
Gamers! is probably the only series on this list that doesn’t have its roots in some sort of fantasy world. The series follows Keita Amano, a young boy who finds himself invited to his high school’s video game club by Karen Tendo, the most beautiful girl at his school. When he finds out the club is about competitive gaming, he turns her down, which topples over a series of dominos that sets this comedy into play. The series manages to balance humor with some pretty insightful (and often incisive) comments about gaming as a whole, helping it to worm its way into the hearts of anime/gamer fans everywhere.
5 FATE/STAY NIGHT
If Fate/Stay Night isn’t one of the best light novel anime series, it’s certainly one of the most popular ones on this list. It got its first adaptation back in 2005, but the popularity of the franchise dictated that this wasn’t nearly enough, leading to the series getting not only a prequel in 2011, but a remake in 2014. Since then, the franchise has continued to chug along, giving us plenty of new video games, manga, light novels, and multiple animated versions of the universe’s fabled, ever-occurring Holy Grail War, even spinoffs featuring popular characters from the franchise.
4 LOG HORIZON
About a year after Sword Art Online set the anime world ablaze, the “trapped in a video game” subgenre of isekai got a big contender in Log Horizon. When everyone finds themselves unable to log out of the MMO Elder Tale, and were then forced to try and survive in their favorite game.
Where Sword Art focused on surviving in a world where death was the end, Log Horizon took the other direction. With death meaning respawn, the characters are forced to learn everything from how to cook actual meals to how to create a working economy. But what really makes the series stand out is its usage of actual, in-depth MMO mechanics and strategy for its combat scenarios, lending a truer life feel that Sword Art never even tried to aim for.
3 RE:ZERO - STARTING LIFE IN ANOTHER WORLD
Re:Zero is basically if Groundhog’s Day somehow became an anime. It’s lead character Subaru is a guy from the real world who enters an alternate, fantasy-like universe with one unfortunate ability: he can come back to life after he’s killed. An ability dubbed Return from Death, Subaru gets to utilize this ability to help not only himself but those around him, as coming back to life reverses time, often going back to right before a situation goes for the worst. The series gained massive popularity for its gorgeous animation courtesy of White Fox, but also its likable cast and the unique way each new scenario unfolds. It was even popular enough to survive its first season, with the second coming in 2020.
2 LEGEND OF THE LEGENDARY HEROES
Takaya Kagami’s Legend of the Legendary Heroes novel series was such a massive epic he needed two dozen novels just to set the stage for the story he actually wanted to tell. The story follows Ryner Lute, a soldier cursed with a magical eye power known as the Alpha Stigma, allowing him to copy any spell he wishes.
Ryner works alongside his partner Ferris to recover powerful items known as Hero Relics for their country. It’s a straightforward enough premise, but Kagami sets up such a compelling world filled with political intrigue and magical powers that it’s almost criminal it ended after a single season, and pretty consistently makes Most Wanted Sequels lists.
1 THAT TIME I WAS REINCARNATED AS A SLIME
Reincarnated as a Slime takes the isekai genre and has fun with some of its tropes. Its main character is Satoru Mikami, a salaryman who dies as a 37-year-old virgin and is reincarnated as an invincible slime known as Rimuru, capable of consuming anything.
In this new world, Rimuru works to carve out happiness for him and his newfound monster friends. In Reincarnated as a Slime, fights are just as likely to be resolved by cooler heads discussing diplomacy as they are battles to the death. Having one of the most genuinely affable leads in anime, it’s no surprise the series was renewed for a second season.