I'm sorry if I make you feel old, but I did an essay on spacewar...in history.
My favourite childhood game(Technically I'm still a child, so this is when I was 3-7 years old) is a psx game called Sukoden. I didn't understand a word of it(I couldn't even read my own name), and never got far into it, but I spent hours walking around the starting town. I recently started playing it on my ps3, only properly this time. I also loved crash bandicoot cortex strikes, with about the same amount of success, play-wise, as sudoken.
The first game I enjoyed, and actually managed to play properly, was Tetris DX for the gameboy.