http://www.goodquotes.com/famouslastwords.htm
Some of those are high quality. I hope I can think of something grand like that when I am uncerimoniously executed.
-:DRivE:-
The best way is to have one prepared beforehand
"Now, now my good man, this is no time for making enemies."
Voltaire, on his deathbed in response to a priest asking that he renounce Satan.