Gohan
Died in the future by the Androids.
Died when Buu blew up the Earth.

Vegeta
Died once on Planet Namek at the hands of the evil tyrant Frieza.
Died once more on earth as he self destructed in an attempt to kill Buu.
Killed by the Androids of Dr. Gero on earth in the Alternate future.
Died when Buu blew up the Earth.
Even though he has died a lot he has killed the most people in DBZ.

Piccolo
Died once on earth in the action of jumping on front of a blast let off by Napa that was going right at you.
Killed by the Androids of Dr. Gero on earth in the Alternate Future.
Died when Buu blew up the Earth.

Yamcha
Died once in the battle with the saiyans on earth.
Died again in the battle with Freiza.
Killed by the Androids of Dr. Gero on earth in the Alternate future.
Died when Buu blew up the Earth.

Tien
Died once in the battle on earth with the saiyans.
Killed by the Androids of Dr Gero on earth in the Alternate future.
Died when Buu blew up the Earth.

Chaoutzu
Died once in the battle with the saiyans on earth.
Killed by the Androids of Dr. Gero on earth in the Alternate future.
Died when Buu blew up the Earth.

Frieza
Died once at the hands of Trunks on earth.
Was supposed to die again in GT in the next dimension.

Cell
Died at the hands of Gohan on earth. Was supposed to die again in GT in the next dimension.

Krillin
Was killed on earth by the Demon Piccolo.
Was killed on Planet Namek by Frieza.
Killed by the Androids of Dr. Gero on earth in the Alternate future.
Was killed when Buu blew up the Earth.

Dende
Killed on planet namek by Frieza.

Nappa
Killed on earth at the hands of Vegeta after he failed to defeat Goku.

King Cold
Died at the hands of Trunks on earth.

Zarbon
Dies after transforming at the hands of a renewed Vegeta on planet namek.

Dadoria
Was given a free pass to the next dimension by Vegeta on planet Namek.

Jeice
Was blasted into pieces and was sent to the next dimension by Vegeta.

Burter
Was killed with a massive blow by Goku, which was followed by a blast thrown at Recoome by Vegeta that affected him, on planet namek.

Recoome
Was blasted to the next dimension by Vegeta after Goku had knocked the air out of him on planet Namek.

Godo
Was sent to the next dimension, as he was attempting to dispose of Krillin and Gohan in a mind freeze, by Vegeta on Namek.

Radditz
Killed by Piccolo and Goku on earth as Goku held him and Piccolo blasted him.

Android 19
Killed by Vegeta on earth after Vegeta transformed into a super saiyan.

Android 20: Dr. Gero
Died at the hands of his own creations; androids 17 & 18

Android 16
Was crushed by Cell on earth

Android 17
Was defeated by the Z team on earth.
Was kill when he was Super 17.