Azumanga Daioh is a classic!
Personally, I'd list these titles in my top five, not in any real order.
1. Dragonball (Z is okay too, but I prefer little Goku, he's a lot more fun)
2. Doraemon
3. Future Boy Conan
4. Azumanga Daioh
5. Kodocha
Mind you, these are all TV, it would be a lot harder...