A word thought to describe someone who obsesses over videogames but was actually a term used earlier by Ken Nordine, the spoken-word story-telling Jazz musician in his song "The Vidiot" to describe someone who obsesses over television. This term was used before it was applied to games but has now become most popularly associated with them.
Person1 (to Person2): How many hours do you spend a day watching television?"
Person2 (to Person1): Oh... I don't know... about 18...
Person1 (to Person2): You're a total vidiot, man!