Hakuouki and Amnesia are two favorites of mine. They are based on otome games, which can also be fun if you like reverse harem animes. I will warn you in advance though, that Hakuouki has a sad ending. I didnt see it coming and was upset for a good two weeks straight, but it is still one of my all time favorite reverse harem's because of the stunningly beautiful art and the seriously in depth story line (a rarity for these types of shows.)