Astro Boy is the most famous, and one of the earlier, works by Osamu Tezuka, who basically created Japanese comics. Formative it may be, but also extremely competent. While the series may not quite have the level of character development that we expect from our comics these days (or, indeed, from Tezuka's later works) many of the regulars do come through very clearly, and the old school comic book aesthetic of crazy idea, after crazy idea, after crazy idea is absolutely wonderful.