This one is easy, since my Dad only ever owned one rifle, one shotgun, and one revolver.
The revolver is a Charter Arms .38, that he still has, the shotgun was a Winchester 1897 16 ga. that he inherited from his grandfather, and which now resides with my brother.
The rifle is a Winchester 1906. About 15 years ago my Mom & Dad went "on the road" in an RV, and gave me first dibs on either the '06 or the '97. This was an easy choice, since the '06 is in original condition whilst the '97 had been refinished about 10 years before then. Also, the '06 is the first firearm of any type that I shot, at age 8. We put many a brick of .22 ammo through it when I was a kid, and I still give it a good work-out from time to time.
It isn't the prettiest gun in my safe, but it is my favorite. it was given to my Dad when he was 8, back in the time when my Grandfather owned a Connecticut general store, and my Dad would bug him almost daily for a rifle. One day, a travelling cheese salesman told my grandfather that he was a cheap skate, and pulled this .22 out of his trunk. It had probably bounced around in there for quite some time, and had seen some rough handling since it left the Winchester factory in 1925. Yet, it still shoots straight, and feeds everything, shorts, longs, and long rifles (as well as Colibris), without a hitch.
My Dad is still around, and he and my Mom moved to our town about a year ago. He occasionaly goes to the range with me, and enjoys shooting his first (and only) rifle just as much as I do. I would be lying if I said that he didn't like to sometimes put some lead down range with my Garand or one of my other rifles, but the old '06 is still the champ.