.30-06 is probably the best all-around cartridge for North American game. There are a ton of great guns chambered for it. Also, lots of high-quality ammuntion out there for it as well. There isn't much out there that you couldn't hunt with that gun.
I have had great success with a Savage Model 110. It's not the prettiest, it's not the most expensive. It's not a good gun to take to the range and fire a lot of rounds through. However it's a great hunting rifle. So good, that between my father and I, we have three. He shoots a .30-06 and I have a .270s. With that gun, I've dropped deer at 20 yards, and one at 230 yards.
My newest addition is a Benelli Nova 12ga. It's my new all-around gun. Already dropped a few teal with it this year. Just bought a couple boxes of 3-1/2 inch Hevi-shot for goose season on the river. Furlough has it's advantages!