Hmm, aged 5-10? Possibly Prince of Persia (the original DOS version). I was 10 when I played it, I guess. It was so awesome, quite a step up from other games of that time.
Then there was Hero's Quest, around the same era. My first RPG experience.
Oh! And Solomon's Key. Seemed so cunningly designed back in the day.
*Sob* I still have such fond memories of my first PC... I had to make do with it from the age of 8 to 16... cutting edge when we first bought it, I think you can imagine that it wasn't quite so cutting edge by the time we upgraded
