1988.
That was the year SMB2 came out, and I begged and begged my parents for it. I read the premiere issue of Nintendo Power so many times I had completely memorized the SMB2 spread in there.
Come Christmas morning, I had opened all of my gifts and, sadly, no Mario 2. We were always spoiled by our parents at Christmas, so it was hard to be TOO disappointed while sitting there surrounded by other toys, but then my dad reaches into the linen closet and says, "oops, we forgot one..."
Just from the size of the package, I knew what it was, and as soon as I saw the tiniest bit of that blue box I went nuts. My parents had a hell of a time pulling me away from my NES to go to the family Christmas at my aunt's house.
Also 1994. My parents were actually getting divorced by then, but my dad kept trying to outdo my mom, so he bought me a SNES, MKII, and Donkey Kong Country. Hooray for parental guilt, I guess.