Warning: Some nudity, not terribly explicit, although there is a rape scene in the manga. If you want an indication of its content, it ran in Hana to Yume.
Acquisition Method: Both the anime and manga have been licensed by VIZ. The anime is out already, and the manga is still being released.
Format: 21 volumes of manga, complete. 6 OVAs, complete.
Genre: Sci-fi shoujo, reincarnation, romance?
Plot: A group of young people have recurring dreams about their past lives as alien scientists who observed Earth from a base on the moon. The series is about the attachment, guilt, and obligation they feel toward the past as they recall the events that transpired leading up to their deaths, and how these affect the lives they are living now.
Characters: Six teenagers and one kid, their past incarnations, and various relations and allies. The main characters are Alice Sakaguchi, a shy, plain girl who has just moved to Tokyo, and Rin Kobayashi, her bratty little next-door neighbor.
Seiyuu: Seiyuu list. A top-notch cast, really.
Technical details: Is the translation up to par? Well, there are a few typos in the official sub. I haven't watched the dub, so I couldn't tell you how that is. The animation is absolutely beautiful, on a par with the manga illustrations at their best. The only complaint I have is that it covers only the first few volumes of the manga, then tries to condense the rest or skips over it entirely. The early manga volumes are not so nice to look at, but if you can get past the late-80's style, the art really improves as you go along. It features the most beautiful manga character I have ever seen. Go to the gallery here for some examples of what I mean.
Music: By Hajime Mizoguchi, also Yoko Kanno did the closing theme, I think. How can you get any better than that?
Squee factor: There's probably something here for everybody. The anime is nearly flawless, the storyline is epic, there's a plot and detailed, developed characters, there's action and romance. The main het couple's relationship is both compelling and disturbing, there's canonical shounen-ai, and there's enough subtext to make plenty of het/slash pairings viable. The whole thing makes X look like crap, I'm serious.
This is a classic series, and I think many people have seen the OVAs, but few have read the manga, and whatever fandom existed is long dead. I'd love for it to make a comeback. I've started a LJ community for it, ps_myearth, so feel welcome to join.