2nd.
The .223 is great for cheap, recoil-less practice and varmint shooting. The .25-06 is the ideal deer cartridge, and a fantastic long-range coyote gun. It doesn't get much better than a 7mm Rem Mag for moose, elk, bear, and long-range shots at deer. The .375 is great for hunting grizz or polar bear, and perhaps hunting moose and elk in the dark timber.
The .375 is heavier, and has more recoil and gun powder than I want to put up with for your average moose or elk hunting. The 7RM has more recoil, muzzle blast, and powder consumption than I want to put up with for deer hunting. The .25-06 makes a mess of coyotes if you're worried about the hides. The .223 is perfect for the smallest of chores, or for a full day of long-range target or varmint shooting (a couple hundred rounds of 7RM gets tiring after a while).
Keep 'em all!!