Before there was a Harry Potter there was Mildred Hubble, the gawky, unpopular worst witch at Miss Cackle's Academy for Witches. Instead of always battling pure evil and saving the world, she more often has to battle catty rich witches and spends a lot of time in an awesome cake shop that I daydream about like a lonely preteen.
Most of you might be more familiar with the Fairuza Balk, Diana Rigg, Tim Curry movie version that preceded the television series and got a lot of air time in our youth. Based on the Jill Murphy collection of books, The Worst Witch is charming and fun in all formats. I've enjoyed hours (there are four full seasons worth) of the 1998 series starring Georgina Sherrington and I just found out that the series continued into 2006 with The New Worst Witch (which I have not seen yet) which follows Mildred's equally hapless cousin.