I recently found out that Cities of Gold is technically anime, so it'd be that, the first time it was shown in English back in the '80s. The first I consciously saw was Akira, it was shown (IIRC) in 1991 on channel 4 at 11pm on a friday night ... I couldn't watch it, but I had a friend with a video recorder who got his Mum to set the timer for me. I watched it at school the following week (in bits during lunchtimes, thanks to a sympathetic teacher), and kept the tape even though I wouldn't have my own VHS player for another 6 years, lol ... it totally blew me away at the time, and I think it's aged well :-)