I basically grew up playing video games and my dad got me to start playing when I was basically 3, first game was of course DOOM. But I had many, MANY other games I played, some obscure and others well known. And funnily enough my favourite game growing up was Monoliths AVP2, as a kid marine campaign was 2Sp00k13 so I always played Alien and Predator. I still have the disk lying around and I play it every now and then and yes I did eventually beat the marine campaign when I was older.
I will admit I played games that really weren't for kids as a small child but my god were they fun, a few examples of games kids shouldn't play is Postal 2 or The Suffering yet I played them.
So my question to you, what are your games that you either have massive nostalgia for and still enjoy or what games did you play when you really shouldn't have but loved it anyway.