This show has to be one of the best I've seen in a while and I'm sure if I'd seen any other Mahou Shoujo shows this would be one of my favourite ones. After the long delay caused by the tsunami and earthquake Madoka managed to slip to the back of my mind, especially with the start of what looks to be an exceptional Spring season distracting me further from it. In order to make up for this I re-watched the first ten episodes the day before the two finale episodes aired, and I'm glad I did otherwise the ending probably wouldn't have had the same impact if my connection to the characters hadn't been rebuilt. Having already seen the ten episodes once, re-watching them enabled me to appreciate certain aspects more, such as the mirroring between episode 10 and 1 where Homura and Madoka walk through the halls of the school.
The animation of the series is also pretty good. The character designs are smooth and each character is easily distinguishable from others, with everyone having their own distinct look. The only problem with the animation was that the character animation was occasionally off, but there are few anime where this s not the case, so I'm not going to pick on it too much. The backgrounds are also very clean and also very detailed in some cases. The backgrounds for the witches domains are pretty trippy and strange, but they suit the crazy world of magic and the creatures within them, and the actions scenes that take place in them are usually pretty well animated too. Complimenting the animation, there is also a pretty good soundtrack with a number of memorable tracks, with the OP and ED carrying on the Winter seasons theme of quality OPs and EDs.
The characters were each very different people to one another, with back stories provided for Kyouko and Homura which explain how they came to be the person they are today and helping you to connect to them even more, especially with Homura's back story, which encapsulates the whole of episode 10. Kyubey (pictured above) is also an extremely unique character, the sort of which I haven't really seen in other anime. His adorable appearance with its permanent :3 face is contrasted against the blunt, arguably evil genius the hides within, taking advantage of others for his own (and his species') desires.
The ending itself was brilliant, and definitely the best of the 5 shows I was watching that ended last season. Most of the developments within the last two endings were completely unpredictable (at least to me) and episode 12 in particular was very emotional for those who had formed a connection with the characters through the 12 episodes. As expected for a finale of a show with magic and monsters there was an excellent action sequence in episode 11 as Walpurgis Night arrives, with a ridiculous amount of military-grade fire-power. The twists in the final two episodes were also very characteristic of the rest of the series, with its revelations, deaths and character developments of the first ten episodes.
In summary, Puella Magi☆Madoka Magica is almost definitely going to be one of the best anime to air on 2011 and judging by the sales of the first Blu-Ray/DVD release it can easily become a classic. Madoka showed itself to be unique, at least in terms of the Mahou Shoujo genre, from episode 3, and manage to keep up the break-neck pace, unpredictable twists and turns and character development all the way until the end, making for an emotional and action-packed final two episodes, which failed to disappoint even with all the expectation and hype that had built up among fans during the weeks it was delayed. Even halfway through the series' 12 episode run this show managed to jump right into my top 10 or even 5 anime of all time and I'll almost certainly be watching the series again when all of the episodes are released in Blu-Ray, with improved visuals which will undoubtedly enhance the series further.
EDIT: The first Blu-Ray volume sells 53,000 in first week to break previous record of 51,000 set by Volume 6 of Bakemonogatari