The one for me which has always worked like Thor's hammer is the 450 Marlin Guide gun. The longest shot I have taken is with this as well, 220 yards with a 2 3/4 power scope.
My best and favorite rifles are the oldest; a Flaig's custom Mauser 30.06 caliber which puts 165 grain Core-lokt's into an inch at 200M, and my Dad's old Marlin 30-30 (circa 1956), 5/8 to 3/4 inch with the Lever evolution ammo. I like to mess with various rifles and cartidges, but the standard ones are what I circle back to.
Oh, can't forget the Winchester Model 70 7mm Rem Mag with BOSS...1.5 inches at 300 yards. This round is quite disagreeable to most everything. I like magnums and big knives whether they are required or not; you can't shoot something too hard, you can shoot it badly though.

On the other end of the spectrum, I love me a 17 HMR, dropped a hog in its tracks with one at 60 yds, little 17 grain placed properly is quite disagreeable too.