There's something about Pern that just begs to be filked...
Empty Chairs at Empty Tables - Not so much a filk as looking at almost the same words from a different perspective. I was listening to Les Miserables while killing off a much-loved character in a Threadfall and this song hit me quite hard.
Do you have some filk you want added? Send it to me at kharanth@geocities.com and it might go up. Of course, I'll credit the author and give a link.