That's a tricky question. I think things from each version, but then I have my tiny dislikes as well. Erm....I KNOW!
1963 AstroLikes: First ever version of Astro in anime format! :3 Totally dig the squeaky boots and his strong sense of justice.
Dislikes:Prefered voice actor in early episodes, sometimes he was drawn funny but forgivable since it is the 60's x3
1980 AstroLikes: SO CUUUUTE! I just wanna adopt and take him home with meee!
Dislikes: TOO CUUUUTE! He gets pushed around, shot at and hit in the head with a bottle. Too much of a pansy.
2003 AstroLikes: Arm cannon is cool, Astro's a sweetheart (Japanese only >.<) yet a determined hero who is a pacifist, rather seeking the peace than war.
Dislikes: They censored the machine guns and Astro isn't allowed to punch or kick, he just swerves and dodges attacks like a ballerina
2009 AstroLikes:...(hugs) I love you
I really really love you! And Freddie Highmore for voicing you, but don't tell him that okay?
Dislikes: Should've shown his classic costume a bit more for the sake of the fans, would've prefered he looked more robotic, but hey interesting concept being made human no less.
Pluto AstroLikes:...(eye twitches) I have no comment, I like the plot of Pluto but I just don't like the art style, the characters are no longer them and it doesn't feel like a Tezuka world...>.<
Dislikes: YOU'RE NOT ASTRO YOU'RE AN IMPOSTER! :d oh: (chases him down with a chainsaw)