Claims that if you don't send it a million dollars, it's programmer will take it back. It just hurts. Inflates itself to a size bigger than any other files, threatens some and then deletes itself. Beats up all the other viruses. Visit's your Hard Drive about thirty times, each time your hard drive's screwed.
Files dissappear only to turn up years later in another directory.
Buys out all other files and then charges them to run. It quickly assimilates your computer, Resistance is futile. Easily deleted but comes back 1000 years later and kicks you hard drive's royal ass. Makes your whole computer go down. Quits after one byte.