My Hero Academia: Sub or Dub?

This is one of the easier calls on the site, and the reason has nothing to do with the acting, which is good on both sides. It is that the main character's name is a joke, and the joke is in Japanese.

The short answer

Either. Take the dub if you want to watch without reading, because it is well cast and it arrives fast. Take the sub if you want the wordplay the entire premise is built on to land as wordplay rather than as an explanation.

The dub is good, and it is quick

Justin Briner plays Izuku and Christopher Sabat plays All Might, which is a piece of casting that solves the hardest problem in the show: All Might has two voices, the enormous public one and the hollow one underneath, and the part fails if a single actor cannot do both. Funimation ran it as a simuldub, with the first episodes landing on the same days as the Japanese broadcast, so unlike most of the series on this site there is no penalty in episodes for choosing English.

The show also happens to translate cleanly. Its register is shonen sincerity delivered at volume, English-language voice acting has decades of practice at exactly that, and the school-tournament structure gives actors clean, self-contained scenes to build a character across. "Plus Ultra" survives intact for the simple reason that it was never Japanese to begin with.

The one thing that does not survive

Deku is an insult. It means a wooden puppet, and by extension someone useless, which is why Bakugo uses it. The turn comes when Uraraka says she likes it, because to her ear it sounds like dekiru, the verb for being able to do something. The nickname flips from "you can't" to "you can" on the strength of two syllables, and Izuku takes it as his hero name later precisely because of that flip.

English cannot do this. The dub keeps "Deku" as a name, which is correct, and then has to let Uraraka explain the resemblance to a word the audience has not heard. It works, in that you understand it. It does not work in the way the Japanese works, where you hear the pun before anyone tells you about it, and the reversal happens in the same instant the line does. We wrote the word up in full on our what does Deku mean page, which is worth reading either way, because the pun is doing more of the storytelling than a first watch suggests.

Which to pick

New to the show and hoping to keep up week to week: the dub, without hesitation. Rewatching, or coming to it after reading the manga: the sub, because the second pass is when the naming, and the way characters address each other, starts to matter more than the fights.

For sequence including the films, see the watch order; if you have finished it, the ending is explained here. Izuku's lines are on his quote page.