Mine would be my Winchester 72A. Its a very handy tube fed bolt action. It was my very first rifle, and I developed some very find memories with it. My Grandpa gave it to me when I was 13 and before that my grandma had used it to win piles of medals in smallbore competition. Its a real tackdriver.
And I can say from one bad incident...if I was an invading alien, I wouldn't want to be shot by it. When I was 15, I was out in the desert shooting coke cans off boulders, and caught a ricochet in the calf. Hurt like crazy, and did enough damage to require a minor surgery. Lesson learned.