Oh, gosh. I don't even... Hm. I wanna say 9 or 10. OoT of course.
I used to watch my dad and older brother play it, and I remember being enthralled by the concept of controlling a character and battling evil throughout a storyline. I remember being piss-scared and hiding behind the couch when my dad faced Gohma, telling him "be careful, daddy!" The memories! Now I have a strong urge to play OoT.