Ponyo
Still proceding through my ghibli journey and I will definitely think i am not able to give less than 5-stars to ghibli's movie.
Ponyo is one of the few films that gave me tears of joy. It's such a magical film with vibrant colors, it catch so well the feeling of amazement you felt when you were a kid discovering the world around you. It even suceed in making you feel those emotions again.
Imo, it's totoro but make it better by having some totally crazy psychedelic scene.