RE: around 98...
I had the wav files from the Dark Reign game for most of the events on my work computer, with the extremely grating maniacal laugh of the suicide bombers occurring quite often. The manager came in one weekend and wiped all the sound files...
In the modern era, I have downloaded a bunch of amusing (briefly) or quirky ringtones, but actually mostly use clipped songs from my own library.
All of which maintain their freshness as I keep my phone on silent for 2 weeks out of 3