"Z"

Zanzouken: A very neat technique in which the attacker moves so fast that they create an after image of themselves.
Krillin, Jackie Chun, Goku, Piccolo

Zanzou Majyutsu: Instead of the attacker moving so fast an after image is created, the image is created with magic.
Darbura

Zenshin kara no Shyougeki Ha: Arms and legs are spread out, and a powerful explosion of ki is sent in every direction.
Vegeta and Fat Buu

Zutsuki: Head-butt to chest.
Arale Chan