I didn't get into this serious until I watched it online (I couldn't wait for one of AS' reruns). I think what initially grabbed me was the ridiculous humor and light-hearted nature of the show. I really enjoyed watching something that wasn't overly serious and filled with typical anime conventions that took themselves seriously.
Once I got past the humor what was left was a sweet story of a boy coming into his own, thanks to a space pirate, generally aloof friends, and an incompetent goverment agency. That's what I took away from the show, and what resonated with me as I was (and still am) going through much of the same general experiences.
Note: The word "General" omits the presence of awesome robots and sexy space pirates. 
"You're the ultimate troll. Your rank on the boards should be HE WHO TROLLS AND IS TROLL OF ALL TROLLS. Troll."
Anani