Goku died twice.
Vegeta died twice.
Piccolo died twice.
Gohan died once.
Tien died twice.
Chaotzu died three times.
Krillin died twice (three times total if counting original DragonBall).
Yamcha died twice.
Goten died once.
Trunks... technically died twice. But it was two different Trunks... So one each... I'll count it as twice.
Bulma died once.
Chichi died once.
Master Roshi died once (twice if counting original DragonBall).
Videl died once.

Of all the important and somewhat-important characters, only one never died...

MR SATAN