The "kids" rifle shared by my brother and I was a Marlin 60. (Colt556 - no jams. )
The first one of my own was a 7mm Model 93 Mauser.
An M16-A2, handed to me by a Drill Sergeant at the beginning of basic training.
First rifle I bought, if that's what we're going for, was a 1903-A3 I bought a little while after high school.