Well, since I already have a 270WSM and a 6.5x55, I voted for the .223. Great cartridge for fun shooting, varmint punching, and up to coyotes. Cheap, plentiful accurate factory ammo available and easy to reload for. Hard to assemble cartridges that won't group well, if your rifle is anything other than a Mini 14. I am sur the 25-06 is also a fine cartridge, but I have never owned or shot one. I miss my old Savage 110GV in .223. Probably the most consistently accurate rifle I have owned, and certainly the most deadly on untold ground squirrels, rock chucks, and a big badger.