Commander Keen is a computer game from 1990 that changed the world as we know it.  Well, maybe not.  But it was cool when I was like 10.  Keen 1 - Invasion of the Vorticons Episode 1
Keen 2 - Invasion of the Vorticons Episode 2
Keen 3 - Invasion of the Vorticons Episode 3
Keen Dreams
Keen 4 - Secret of the Oracle
Keen 5 - Goodbye Galaxy
Keen 6 - Aliens Ate My Babysitter #entertainment