Most anime fans are introduced to the medium through a "gateway anime." This is a show that is generally watched very early on by an anime fan, leading them to explore other shows within and outside its genre. These are shows you would recommend to new fans of anime, or to those who have never seen one in their lives—ones that non-anime fans would think of when they hear the word "anime." Shows like Attack on Titan, Cowboy Bebop, Death Note, both adaptations of Fullmetal Alchemist, Sword Art Online, Ghost in the Shell, Fruits Basket, Ouran High School Host Club, Tokyo Ghoul, and Studio Ghibli movies such as Spirited Away, My Neighbor Totoro, and Howl's Moving Castle are all prime examples of gateway anime. These anime are generally considered a good way to start exploring the medium since they can interest even the most indifferent person. Why are these shows good starter anime? What do they do differently from other anime that elevates them to gateway anime status? There are a million possible explanations for each one, but I'm going to list the main reasons why they are considered good starter anime.
One of the biggest reasons that these shows are gateways is that most of them are renowned productions seen by most anime fans. Popularity doesn't necessarily mean high quality; rather, it indicates that a lot of people within the community have seen the show and will be more inclined to recommend it. Considering the fact that most traditional gateway anime are extremely popular within the anime and manga community, this makes perfect sense. This is made apparent by data on MAL for most of these series.
Data taken 4/26/2017
The shows listed above are among the most popular anime on MAL, including five of the top ten. Being popular makes a show a better gateway anime for two reasons: it allows those interested after watching it to easily get involved in community discussions, and it makes it easier for those already in the community to give recommendations. Since most people in the community know these shows pretty well, they can easily guide newbies to other shows they will like based on their opinions of the initial gateways.
Another reason that these shows are gateway anime is due to their perceived quality among anime fans. This may seem completely obvious, but it's generally true. When introducing a newcomer to anime, it's a good idea to show the best of what the medium has to offer. And these gateway anime are considered some of the best, as indicated by their MAL rankings.
Data taken 4/26/2017
The reason for this is simple: it might be fun to recommend something like Mars of Destruction or Pupa for a joke, but when you're trying to introduce someone to the medium, it's best to show them the cream of the crop, the best of the best, something that is truly great. This keeps them interested in the medium and allows them to experience everything anime has to offer.
In addition, most gateway anime have high animation quality, strong visuals, and unique character designs. Since anime is a visual medium, it's important to see what the premier studios are capable of rather than what a mediocre one can do. And what these studios are capable of are truly spectacular. Powerhouse studios like Bones, A-1 Pictures, Studio Ghibli, and Madhouse are considered some of the best in the business. They show this in almost every way possible by using strong shot composition, incredible editing and camerawork, and beautiful animation. A good starter anime needs to have stunning visuals as a hook because that's the most effective way to attract casuals and newbies to a show. If a show has an incredible story, but looks terrible, it won't be an effective gateway anime.
A strong point of most gateway anime is their OP, both in terms of song and visuals. The songs Tank! from Cowboy Bebop, Again from Fullmetal Alchemist: Brotherhood, Guren no Yumiya from Attack on Titan, and Unravel from Tokyo Ghoul are some of the most recognizable OP's in anime. The visuals for the OP's are usually just as spectacular, containing layers of meaning as well as beautiful imagery and good editing. The following OP's from Fullmetal Alchemist: Brotherhood, Attack on Titan, and Death Note are some great examples.
While this is a small sample of the shows mentioned, this is consistently true across the board. A gateway show often features an excellent soundtrack, but the OP is the main selling point because it serves as the initial preview of the show. A good OP is critical to interest a newbie in the rest of the show.
An interesting aspect of most gateway anime is not being set in modern-day Japan. Attack on Titan, Fullmetal Alchemist, Howl's Moving Castle, and Spirited Away all take place in fantasy worlds; Cowboy Bebop, Ghost in the Shell, and Sword Art Online are set in the future; Tokyo Ghoul, My Neighbor Totoro, and Fruits Basket are set in an alternate fantasy Japan. The exceptions here are Death Note and Ouran High School Host Club; however, they do not require extensive understanding of Japanese culture and norms, and could take place anywhere in the world. This last point applies to Death Note in particular, but is also true for Ouran High School Host Club to a certain extent. This is because introducing a new medium with lots of unfamiliar cultural aspects can be overwhelming and difficult to understand for foreign viewers. Introducing someone to a story that doesn't have too many specific cultural references is a good way to guide them slowly in learning the culture, rather than cramming it in and making it feel like an infodump. This is especially true for westerners who tend not to know much about Japanese culture.
Another common trait among gateway anime is a simple, easy-to-understand initial plot and conflict. This is not to say that the plot cannot be deep or complex, as that is obviously not the case with shows like Attack on Titan and Fullmetal Alchemist. The key is that the initial setup is very simple and easily describable with a sentence or two. In Attack on Titan, Eren Jaeger strives to join the Survey Corps in order to defeat the Titans after one killed his mother during the fall of Shiganshina District. In Fullmetal Alchemist, Edward and Alphonse Elric seek the Philosopher's Stone in order to get their bodies back after they lost them while attempting human transmutation. Another example is Death Note, where Light Yamagi seeks to bring justice to criminals and make the world a better place by using the Death Note brought to Earth by the Shinigami Ryuk. The initial setup in these cases is the conflict established very early on in the series—within the first couple episodes. Shows like Pandora Hearts and Serial Experiments Lain, while generally considered good in the anime community, have complex, confusing initial setups where things only become clear many episodes down the line. As a show for a seasoned veteran, this can work very well, but as an introduction for a newbie, it's best to stick to something that keeps the plot and conflict clear and concise from episode one onwards. Even in gateway anime with more complex plot points like Fullmetal Alchemist, it's always perfectly clear what the central conflict and overarching story actually are. This helps ease a newbie into the show better and prevents them from getting confused and overwhelmed by vague plot details, instead allowing them to fully appreciate the show and the medium.
The final main aspect of a gateway anime is a shortage of fanservice. This is not to say that they cannot have any fanservice whatsoever, as most of the shows listed above have at least one or two moments. However, shows heavy in fanservice like Highschool of the Dead and Free! are generally lacking in the aspects listed above to be a good gateway. They are often slightly less popular and not of the same critical quality compared to the previous examples. They can be enjoyable in their own right, but using shows like these as an introduction to the medium can give the wrong impression to an unknowledgeable viewer, thus leading to harmful stereotypes about anime in the West. Some believe all anime to be about fanservice and harems, and if their introduction to the medium is a show that features these tropes heavily, it will only ensure that they will never watch the best of what the medium has to offer.
When selecting a starter anime for someone else, it is important to consider the aspects listed above. Anime is a great medium with lots of incredible stories to offer, but it's also very easy to deter a newcomer's interest by introducing them the wrong way. Most of us remember our first anime fondly, and it's important to let newbies have the same experience. There is no better way to grow the community than to get people interested with a high quality show. Good starter anime are very important for this purpose, so the next time you're picking a first anime for someone you know, keep these factors in mind. You might be able to inspire a love of anime in another person, and there is truly no better experience than sharing your passion with someone else.