*cough* Anyway, this post will be about all three seasons, possibly some of the manga, even less of the sound stages, and none of the movie, since it isn't coming out on DVD until summer T_T. If you haven't seen this before, I urge you to go watch it. You might be thinking, "With a title like 'Magical Girl Lyrical Nanoha'? No way!" But even though it's called that, you'll quickly see that this isn't a normal magical girl show. Oh no. It's even better. Still need convincing (and aren't afraid of spoilers)? Read on!
Edit: Long post is long. If you're in a hurry, I basically summarized the three seasons and talked about main characters. And if you're looking for a reason to watch this:
That is why.