My cherry popper was Mobile Suit Gundam... I was about 5 I think. Maybe a bit younger than that. It was on some fuzzy channel and it was in Japanese, but it looked pretty badass to me as a kid... So I watched it every week. Then I got a bit older, and caught Akira, Sailor Moon, DBZ, etc... You know, all the stuff that was available at the time. ^.^
I can't remember what manga was my first, though... I know I borrowed some from a friend. >.>