There are a bunch for me to choose from but this is the one that I always relate when asked.
Christmas, 1982. Earlier that summer Mattel released the Intellivoice voice synthesis module for it's core Intellivision game. One of the first games released for the Intellivoice is "B-17 Bomber". To say I was jonesing for that game would be like saying a crack addict likes to get high occaisionally. At school, it's all I dreamt of. I mean, think about it. I could take my virtual B-17 out on missions, shoot down 109's, and bomb the hell outta whatever I felt like while having to manage the airplane's fuel and bomb load AND navigation AND piloting AND...ah, you get my point.
About 2 weeks before the big morning I was bound and determined that I had to play that game before the big day arrived. Snooping around the Christmas tree one night, well after the parental units had gone to bed, I realised that one of my presents was in the exact shape and size for the game I so longed to play. My mind went racing. I couldn't just tear into it as much as I'd like to, the parents would see that. Think, think, think....
OH YES! In the garage, in the tool shop, second drawer on the right: Xacto blades!!!! Yes, I was in business!! I went out and got an unused blade (he'd never miss an unused blade, his xacto knife being gone would be noticed in 5 seconds) and took it upstairs with my present. Slowly, carefully, hands shaking, I sliced the cellophane tape that kept the paper wrapping around my present. I made only 2 cuts on the end, peeled back the paper, opened one end of the box and...out slipped the cartridge and gamepad overlays. Holy**** I thought to myself. Every night from then on until Christmas morning I played that game til my eyes couldn't stay open. It was pure bliss, joy as it supposed to be.
The morning of Christmas of course I acted excited and happy as one could fake. I came down the stairs, everyone gathering around the living room, I scan my loot...and my little present is not there. After opening all my presents and not finding it, a small frown came upon my face to which my father asked me if everything was ok. I said no, the one thing that I wanted is not here. He then told me that everything was under the tree and there is nothing left. After a few minutes of watching me pout he pulls out from behind him the little present, pointed to the excessive tape on one end from me reclosing it after every night and told me if I ever did that again my Christmas's from here on out would be much less joyful.
Intellivision B-17 bomber page