Angelic layer and crest of the stars/banner of the stars
The first is a 25 episode series that took a medicocure manga and made it into an amazing anime by changing a few small details* so things actually made more sense.
For a battle anime it's not especially action packed but it's got some amazing character development. It's amazing how expressive the Angels are for dolls that can't speak.
Crest of the stars/Banner of the stars is a series of ovas. It's sort of a space opera about the story of two literally star crossed lovers Jinto and Lafiel and their growing relationship with each other.
Katekyo Hitman Reborn. The first few episodes aren't that great but as the story arc goes on, everything goes well. The story is about Mafias and Hitmans.*