I rewatched Rozen Maiden, Rozen Maiden: Träumend and Rozen Maiden: Ouvertüre (2004-2006) some weeks ago. Afterwards I found out that season 3 (according to Young Jump / Anime News Network) will, finally, air this summer.
Rozen Maiden is about a couple of dolls that is created by the doll maker Rozen. They look like big lifelike dolls and can move and talk and they have wills and personalities of their own like (small) humans. Each of them have a Rosa Mystica which they have to fight each other for, so one of them can become the perfect girl: Alice, and meet their father (Rozen) again. They draw power for their fights from humans whom they've made their medium. The main medium in the series is a middle school boy with a deep trauma which he through the course of the series need to confront.
The first time I watched it was around 2006-2007 on my computer, this time it was on DVD on my TV. It had gone enough time for me to forget a lot of the anime except the characters, overall plot and bits here and there. It made it thrilling to watch again. Last time I loved the first season more but this time I'm unsure since season 2 (Träumend) evolved the characters and their motivations a bit more. The OVA swept my heart away just as the first time (it's a must watch!).
I have ever since I watched Rozen Maiden said it's my favourite anime series, both because of the characters and the beautiful 19th century clothes on the dolls. I don't think it's as insanely awesome after rewatching it as I remembered (Ouvertüre was equally great as before though) but back then I had just started to watch anime so I had nothing to compare with. It's still a favourite though.
I'm continuing to be a huge fan of the series and I still recommend watching it. I will definitely get my hands on season 3 when it's released for us non-Japanese speakers.
1) Suigintou, 2) Shinku, Souseiseki and 3) Hina-Ichigo
Rozen Maiden 2nd Collection by *kuridoki on deviantART