Rahxephon is on my top ten list of must watch anime and I put it personally ahead of Neon Genesis Evangelion because it will not make you have a migrain after watching it (just hear me out before you get all Shinji on me), sorry to those of you who think I am cursing NGE but I am not because this recommendation is for those who are starting out watching mecha & drama anime. Rah, for me was a step in order to understand NGE a little bit better and realize just how good it is (even though I had seen NGE 1st). But for a icebreaker into this genre of Anime it is better to watch this one first and then watch NGE because when you watch NGE you will have to pay attention to every detail and every little tiny hint during the series because while you are watching it, it might seem unimportant at the time but later on during the season it can have a big part in the story. That is why I say you should watch Rah because it has a story that is sort of similar to NGE, but it has a good ending and everyone loves happy endings (except Shinji's). I don't want to give a little detail about the story because it would be a spoiler if I did, so I will just say go out and watch Rahxephon because it is a good steping stone for Neon Genesis Evangelion and if you have seen NGE, you will also enjoy Rahxephon because you get the ending that it should have gotten.