The poor bastard has died a grand total of four times throughout the shows:
Once in Dragon Ball (savegely beaten and murdered.)
Once by Freeza (completly vaporized.)
Once by Majiin Buu (though, who could blame him, since that was the time EVERYONE DIED.)
And finnally of natural causes at the end of DBGT (I can't believe I sat through the whole thing either.)
The only thing separating him from Kenny is that when he's killed, instead of shouting "OH MY GOD!!!! They Killed Krillin! YOU BASTARDS!!!" Goku beats the living tar out of anyone who does.