I second the Tikka, and Howa suggestions, excellent rifles for the money.
There's plenty of people on here with a lot more technical knowledge than me, but from a practicality standpoint, 30-06, 6.5 Creed, 308, 300 Win mag make the most sense, unless you're reloading yourself or have a good source for the PRC/new rounds. I have a bunch of the ELD-X tables saved that compare ballistics that I could include if you're interested.
Personally, for a do-it-all inside 300 yards I'm probably going for 30-06, I don't reload and don't plan to so having ammo available and *cheap* is as important to me as just about anything. All of the rounds mentioned so far, at least with an ELD-X factory are between 6"-8" of drop at 300 yards except for .308.