Home Pong (or a clone of it).

LCD games from nintendo; they had some handheld versions, and a watch game. Later I got my hands on a game boy and started off with Tetris and Super Mario Land. My first non-handheld game I think was Under Starter's Orders, a forgotten racehorse gambling game, and some other ones... a really old version of Falcon and Moraff's Dungeon.

Doom in some fckng old '95 PC with my brother.
I always pressed CTRL and opened the doors while my brother moved the character...man those were good 'ol gory days!!
It actually was pretty scary back then when we were 5-6 years old and pretty damn bloody!
Still play it today. THE most legendary game ever!! :--)!!!

Bagasaurus - I can't even remember the gameplay, just what the game was called. It was on the Apple IIc, if I remember right.

I can't remember for sure, all the alcoholic beverages destroyed much of my memory... ;p
But i think it was some Atari game (River Raid or Enduro)..

On Arcades, i think it was Cabal.. (LOVED this game...)

1981, 3yrs old, Odyssey^2

Showdown 2100AD
Speedway/Spin-out/Cryptologic
Blackjack!

are you implying you didnt start gaming until you were already older?

It would be a toss up between Donkey Kong, Duck Shoot, and Radar Rat Race, on the vic-20.

I'm sure the Three Blind Mice nursery rhyme still haunts my parents' nightmares.