The Andromeda Strain (The Andromeda Strain, by Michael Crichton)Read about another entry on the list.
As alien viruses go, the Andromeda Strain really sets a high bar. Shortly after it touches down on Earth via a crashed military satellite, it infects and kills the first humans it encounters, then rapidly mutates to infect everything else—from humans (wiping out an entire town), to the plastic and metal barriers constructed to contain it. And you thought dinosaurs that could open doors were bad.
--Marshal Zeringue