The first book I read was Light Fantastic and dont know that I would have gone on to read the series (several times) had I not picked Wyrd Sisters.
Granny and Nanny are a double act that bounce off each other. Tiffany .........As of yet I'm not a fan but I'm happy wait and see.

And although I am a Watch & Witch fan in equal measure......the Stick and Bucket dance cracks me up every time :p