I take issue with people who declare Mahou Shoujo Lyrical Nanoha (or one of its sequels) to be the best Magical Girl series ever. The magical girl genre is understandably focused primarily on relationships, the pursuit of love, and other similar themes. Nanoha, meanwhile, is noted for its magical girls engaging in earth-shattering battles with devastating laser barrages and bone-shattering impacts. The general impression I get from people who make the claim is that Nanoha is great because it’s a magical girl show without all the fluff and romance.
In other words, it’s the best magical girl show for being nothing like a magical girl show.
I don’t think this is a case of breaking genre conventions, though the thought occurred to me. It’s different from a show like Evangelion which turned the mecha genre on its ear because Evangelion did not go against what defines the mecha genre in the first place. The characters may have been emotional wrecks, but the common theme of humanity and its relationship with war and suffering is a long-running concept since even before First Gundam, and it’s present in Evangelion with a twist. Princess Tutu, as an example closer to the topic of Nanoha at hand, approaches the issue of meta-stories and the very nature of “story” itself, but it maintains itself as a magical girl series with, again, its emphasis on relationships.
I like the Nanoha series, but the appeal of it is more like a Sunrise mecha show than it is a magical girl series, and I think to judge it from that perspective is a little unusual. It would be like saying that a plate of spaghetti you just ate is the best yakisoba ever, despite tasting nothing like how a yakisoba should. The key word in mahou shoujo is shoujo, and personally I think the fact that Nanoha is basically only a magical girl show on the surface automatically disqualifies it.
PS: If you’re wondering what I consider to be the best magical girl series, Cardcaptor Sakura, of course.