Sort of tangentially related to trooper6's post, but in this case, I want to hear the coolest (or stupidest!) stories of how a player character shuffled off this mortal coil and left a lasting impression with his or her departure.
In an AD&D2E campaign played in college, one of the players (who turned out to be one of the funnest DMs as well) had a PC Bob the Bard (seriously). Somewhere along the way he picked up an intelligent sword named Jinx whose ability, when held aloft and commanded, "Jinx: Let's go!" would teleport the bearer and anything he was carrying or holding in a random direction 100-1000 miles.
We were at the climax of the campaign, having trekked to the middle of a desert to find the evil lich's stronghold, and we were in the throne room engaged in the final epic battle when poor Bob found himself going past -10 HP against the lich himself.
Bob, to DM: "Dying action?"
DM, reluctantly, "Ohhhkayyy...?"
Bob: "I grab the lich's arm, hold up my sword and say, "Jinx: Let's go!"
Poof. No more lich, no more Bob.
(you of course see the problem with this... it spawned a rather nice followup campaign.)