In my opinion Clannad is the best anime.
No.
It was good until they killed Fuuko off. If they had ended it at episode 6, great anime.
But they didn't.
Not only did the storyline change entirely from keeping the memory of a zombie girl alive to socializing and tending to some big breasted bookworm with dead parents, but they managed to keep Fuuko in the anime, reappearing as some sort of side-show gimmick after I had shed tears at the fact she was not only in a coma, but completely forgotten about.
Pisses me off. Pig disgusting story writers.