In my opinion, Robotech was the one that made the most impact on the rating for any anime and probably the most profit for the companies affliated with Robotech.
Yes, Mazinger, G-force, Mach-5 and several others were shown few years before Robotech. However, none were as popular as Robotech, nor do they have other comapnies backing the anime series (Matchbox). If I recall correctly, Transformers and Voltrons began broadcasting on US TV after Robotech became popluar and tv syndicates saw potential profit. Although, most on this fourm do not favor Robotech or its affliated company. fact is Robotech did make huge impact on US kids and media companies view on Japanese Anime.
It may have had the most impact, but it certainly didn't introduce anime to America.
Starblazers is just as popular.