I don't have just 1 favorite rifle, since my stable of weapons has been improved over some 60 years of owning/shooting guns. It's not a huge collection, but each rifle serves a purpose well, so its not easy to choose just one. So...I won't.
My favorite walk-about rifle is a CZ 455, .22 magnum. It's powerful enough to pot critters, cheap enough to shoot a bunch of times, ammo doesn't weigh me down, and it's not so loud that I need to wear earmuffs or plugs to shoot it a few times.
My favorite go-to rifle for critters around the fields near the house is a .223, Rem 700 LVSS. It's accurate and being stainless, I don't have to clean it quite as often. It's short and easy to keep in the closet near the outside door.
For serious game, it's my .270 Win, 700 CDL customized. It hasn't shot a deer yet, but took an 860 lb. moose last fall and it shoots great! The custom stock is very nice-looking and stiff. Can't be a favorite all-around rifle yet, but it's gaining ground.
I have others that leave the safe often and are really fun to shoot or carry around. One is a Mod 69 Winchester in excellent condition, and having receiver sights. Shoot it often indoors at the club, but the one shot the most is my customized, Rem 581 that shoots as good as most target rifles, has a wonderful 1.5 lb. trigger and nice 4.5-14x scope.
NOPE...can't just choose one, and thankful I don't have to.