Azumanga Daioh is about high school life through the eyes of six girls with unusual personalities: Chiyo (the 10-year-old genius), Osaka (the resident airhead), Sakaki (the shy one prone to cat bites), Tomo (the loose cannon), Yomi (the short-tempered one) and Kagura (the resident jock).
This anime is like a good book... once you start you just can't put it down. Hardly any of it makes sense, but that's the beauty of it! I could watch it again and again and it would never stop being funny, cute, and genuinely entertaining.