An anime from the late eighties that fused mecha aspects, fleshed out characters (not always likeable though) and some great storytelling. Which unfortunately has some serious issues, mainly in the pacing. And then there are the infamous island episodes (which were added by demand of the broadcaster). To be honest I didn't watch those (except of 30/31), you don't need them in the flow of story or character development and they can ruin your appreciation of the show.
Regarding the technical aspects the series has suffered less than you would expect. The animation is on the edge of what was possible at the time. At its best (the scenes in Tartessos) there are great scenes and backgrounds that intrigue even today. But of course it can't hold up to today's series. The music is 80's synthesizer stuff that sometimes succeeds in adding a great atmosphere and sometimes bugs the viewer a bit. As the Gainax series that preceded Evangelion, you can see some things that would return in their later work: the animation style (less rounded, more angled), important female characters in a Mecha series (Nadia, Electra) and so forth.
Even if you're not an anime fan, if you liked series like the Mysterious Cities Of Gold or Avatar, you should definitely give this one a serious look;
Available on DVD and for download.