Would it be wrong to print in the (seemingly inevitable) program that I had all usable organs harvested before cremation, then have someone play, say, Janis Joplin's "Piece Of My Heart"?
Other than that, I suppose I could go with Avenged Sevenfold's "Little Piece Of Heaven", making sure to specify that the video has to be shown as well, so everyone can be really glad I opted to be cremated...
(Sadly, the band or their label seems to have disabled embedding of the YouTube video, but it's easy enough to find, and well worth it - assuming you have, shall we say, a certain sense of humor.)
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Sodium is a metal that reacts explosively when exposed to water. Chlorine is a gas that'll kill you dead in moments. Together they make my fries taste good.