Detective Conan, also known as Case Closed, has a long and complicated history. From a wild amount of localizations to over 20 feature-length films, the series has confused more than its fair share of fans. One such bit of confusion among fans new and old is how to get into the series in the first place! With 77 translated volumes of manga, at least different dubs from different companies plus subs, there's no clear-cut way to actually start watching the episodes. Do you start from the beginning, dive into the newest episodes without any context or just watch the "best" episodes?
Though its longevity suggests otherwise, getting into Detective Conan isn't that difficult a task -- once you have a handle on the basic premise and characters, it's easy to pick up anywhere for a good time. That premise is this: a high school detective, Shinichi, is transformed into a seven-year-old by a failed poison and must seek out those who transformed him to reverse it.
To that end, he lives with his crush and her Private Eye Father, solving cases and inching closer to getting his body back. From there, the story follows a basic "case of the week" formula. While character relationships may require a bit more puzzling out for the viewer, Detective Conan is still a surprisingly accessible show that requires little to no context to be enjoyed, though it certainly helps.
For those who do want the context, starting from episode one would make the most logical sense, except for the fact that there is currently no legal way to watch every single episode outside of Japan. Funimation's dub, Case Closed, has completely vanished from legal sources following the rights lapse, and while Crunchyroll is doing great at subbing and keeping up with current episodes, it's missing many of the middle seasons.
Likewise, Discotek's new dub is primarily focused on the newer movies and specials, making it difficult for newer fans to fully understand what's happening. Even Viz Media's translation of the manga is actually a fair amount behind the recent episodes of the anime, meaning it doesn't have the full story.
Following all that, for those wanting to enjoy as much of the series as possible, the best option would be a one-two-punch of manga-to-anime. Viz's 77 volumes of translated manga contain everything you need to know about the characters and every major canon plot beat. While its case-of-the-week formula means that even the manga isn't exempt from filler, it's still much less than its anime counterpart. Upon finishing the manga, you can then jump over to Crunchyroll and start watching from episode 754 onwards.
Unfortunately, you'll still miss about five volumes worth of content as Episode 754, "The Tragedy of the Red Woman (Steam)," is adapted from Volume 82, but it's as close to the complete story as you can get outside of Japan.
For those who just want a basic understanding of the characters before following the new weekly episodes, the best way to do that is either reading Volumes 1, 4 and 7, or watching the equivalent episodes of the first season available on Crunchyroll (Episodes 1-5, 11-12, 35-37). These episodes and volumes should give any potential new fan a solid base of understanding when it comes to the main cast of Conan, Ran, Kogoro and the Detective Boys in terms of personality, motivations and desires. For those looking for a little more, Volumes 10 introduces Hattori Heiji, and the first signs that Shinichi's goal of returning to his original age may be possible while Volume 18 introduces Haibara, who just may be the solution to his height problem.
Once you've gotten a feel for the characters and Gosho Aoyama's writing style, you'll be ready to jump into the episodes that catch your eye and start trying to catch the killers yourself.
Finally, for those who want a highlight reel of the memorable stories, Volume 36 holds a pivotal and dramatic part of the Metropolitan Police Love Story, while Volumes 48 and 49 feature a spectacular clash between the FBI and the Black Organization. However, these plotlines are spread out over multiple volumes, often appearing in the background behind or around other cases. Overall though, the charm of the series lies in its individual cases and in trying to beat Conan to the culprit.