Even if you've never seen a magical girl series, you must know the basic idea: a teenage girl has some sort of magic gem that transforms her into an awesome fighter, and she and her best friends fight monsters and revel in the power of friendship. It sounds like the best thing ever!
Puella Magi Madoka Magica is sort of like the Watchmen of magical girl series in that it deconstructs the idea of magical girls and shows the darker side. In this series, to become a magical girl, you sign a contract with a cute/creepy little floppy-eared cat-like creature. Alarm bells should be ringing already because when is signing a contract ever a good thing. Sign on the dotted line, and you get one wish granted. Anything. Even if it seems impossible, Kyubey can make it happen. Those alarm bells should still be ringing because when do wishes ever turn out like they're supposed to. And also, wait, are you saying that you get a miraculous wish granted and you get to be a magical girl? Isn't being a magical girl awesome? That seems too good to be true! (Spoiler warning: it is.)
All of this is laid out in the first episode, where we meet our protagonist, the titular Madoka, your average middle school girl with a couple of friends (the lively Sayaka and the boy-crazy Hitomi). On the day her life changes, she meets the mysterious Homura and the less mysterious Mami and becomes pulled into the world of magical girls. That's basically how a lot of magical girl shows start, right? I'll bet most of them don't have SPOILER in the SPOILER episode and reveal that SPOILER before SPOILER and finally end with SPOILER.
The show basically subverts the whole idea of magical girls and tries to analyze the actual implications of them. What is their inevitable fate? What is their responsibility? What happens to someone with that much power? What if they weren't really in it to save people? It is also sort of like the Cabin in the Woods of magical girl series in that after watching this show, you can't help but view the rest of the genre through its lens. Is this what's really going on with Sailor Moon? (I don't know anything about Sailor Moon. There's a sailor and she lives on the moon and she fights crime or something?)
But it's more than simply a compelling genre critique. The storytelling is incredibly solid and tight; there's not a wasted minute. I grew to like or love all the characters by the end, and it has one of the most intriguing, fascinating villains I've seen in a long time. Every episode elicited capslock reactions; sometimes my reactions were entirely in capslock because my mind was completely blown and I was pulling out all my hair in agony. And then, amazingly, like a magical girl itself, it transformed into a story about bigger concepts and human truths; I don't know why I was surprised because anime so often does this (Gurren Lagann similarly surprised me). The finale, while not completely satisfying, makes more than enough sense (seriously, this is anime, you cannot expect it to make all the sense) and really pulls together the themes of the show that have been hiding beneath the surface the whole time.
I have to also put in special mentions for the animation and music, which are wonderful. Both truly shine in the fight scenes, as the characters often fight in surreal labyrinths that look like they were designed by the King of All Cosmos, and their fights are backed by an epic, operatic score. I have never seen shit like this before in any medium.
While the series is probably best appreciated with knowledge of more traditional magical girl series, I've only seen the non-traditional Princess Tutu, and I still loved this series. Really, you only need to be aware of the basic idea to understand what the show is doing, and the story it tells does not rely on any specific genre knowledge. Best of all, it's only 12 episodes, and you can watch it for free on Hulu!
Well, almost free. Just sign this contract.