I have always thought that what makes a good sci-fi is not just some high adventure made technically plausible, but a technically plausibility that provokes deep and meaningful conversations. Anime, IMHO has a very rich history of that.
A few things come to mind that I think have been forgotton, and by that I think today are considered greatly underappre... (more)
I think most of the ones I was gonna say we're mentioned already, but I also enjoyed
Teenagers from Mars -and-
As everyone else has stated, it will depend on what you like.
I will state to you what I think are some of the most fun to read and would be good gateway reading.
Classic names: Phoenix by Osamu Tezuka... (more)