the Mahou Shoujo Lyrical Nanoha series. It's one of the few shows I know of that seems to get better every episode and season. Most shows get a degree worse each season and as the series goes on more and more bad episodes pop up. Naonha just seems to get better and better. It had a bit of a shaky start, not getting really interesting till about episode 4 in the first season, but now I'm addicted to Nanoha.