For some reason I like "Death makes angels of us all and gives us wings where we had shoulders smooth as ravens claws." Even though I don't believe in angels.
As for myself...I will be cremated and my ashes will be thrown in the garbage so the closest thing I will have to a headstone with an epitaph on it will be the signs at the landfill that direct traffic.
"Before you is the fulfillment of an ambition that escaped Fosing for a very long time...DEATH. Now it can be said: You can even bring your ambition to the grave."
or
"Finally he has achieved his purpose...he is now fertilizer."
or
"Fosing, died trying to save the princess from another castle."