Mahou Shoujo Madoka Magica, or just Mahou Shoujo is a magical girl drama anime, with a lot of dark twists.
The Plot: Madoka is a pink-haired timid girl who lacks in self-confidence. One day she stumbles upon her classmate, Homura-chan, who is chasing a small, cute white and red fox looking creature. The creature being injured, Madoka tries to help it. It turns out the creature can talk, and his/her name is Kyubey. Kyubey explains to her that Homura is one of many "magical girls" (Mahou Shoujo) that fight and destroy evil witches. Kyubey also explains, that Madoka herself can become a powerful magical girl and she also gets one wish to be fulfilled when she agrees to becoming a magical girl.
The series follows Madoka and the other magical girls, as more is revealed about the true nature of being a magical girl and what is really at stake for them. With that said, much of the entertainment value in this series rests upon: 1. How much you sympathize with the characters. 2. How willing you are to swallow the many "dark" plot twists. 3. How much you enjoy the pseudo-philosophy that it lays out for you.
While Mahou Shoujo is largely claimed to have revolutionized or reinvented the magical girl genre, Mahou Shoujo is still very much a magical girl anime. It has young girls transforming into powerful magical girls and fighting evil. At the end of the series, this premise still holds.
However, what makes Madoka interesting, and why it has garnered so much attention is because of the above-mentioned "dark twists". The life of a magical girl is not the glorified life that the girls thought it would be. Kyubey isn't what they thought he was. And those "evil witches", well let's just say there is a reason they are called witches and not anything else. It's these kinds of plot twists and reveals that make each episode go by. Character development centers around these plot twists. As the girls learn more, the audience learns more.
More often than not, the plot twists result in the girls crying their eyes out because of what they've just discovered. The anime series uses music excessively to help communicate specific emotions during specific scenes. For example, when we're supposed to feel sad, cue sad music. When there's a huge crazy plot twist, cue dramatic symphony music. As such, the anime persistently enforces its ideas of good and evil, and controls who we are supposed to sympathize with.
Something that may cause frustration for viewers, is the pseudo-philosophy. The series certainly touches on many large topics such as, free will and determinism, time, acquiring meaning, existence and the purpose of life. However, the anime mostly uses this to make the viewer sympathize more with the main characters and their struggles.
The last thing I want to talk about is the art style. There are two distinct art styles, one for the real world and one for the world where they fight the witches (which is also used for some flashbacks). The real world looks like your typical anime. But the world of the witches, looks like a demented 5-year old's artistic representation of a nightmare. The style is highly expressionistic and sometimes abstract. Some might be turned off by this. The actions scenes of the magical girls fighting witches in this world are generally what you can expect from any other action anime. There's swords, there's guns, jumping a hundred feet into the air, and stuff like that.
With all that said, Mahou Shoujo is a good anime that breaths life into an arguable dead/dying genre. It lays out its plot and characters in an easy to understand way, while providing some simple-minded food for thought. Mahou Shoujo took risks with its art style and its darker plot. In the end Mahou Shoujo is still a magical girl series. Even though it may rely on our sympathy's for the characters, and the plot is highly structured, Mahou Shoujo does some interesting things with the magical girl genre.
I would recommend this anime even if its just to see how this series builds upon the magical girl template in a new way. However, your own enjoyment of the series may vary based on the 3 points that I mentioned near the beginning of this review.