Minimum caliber for all of N.American game?

[JediMindTricks]

I know nothing of hunting calibers etc. With that said, basically what would be the most cost effective, lightest recoiling round to hunt all of N.American game. The reason I ask is because I can't afford 5 different hunting rifles for 5 different things etc. "The guy" @ my local gun shop said 30-06 because of the many loads there are for it. Someone else said 270 would suffice with proper shot placement for "big" game, and another guy said 7mm. I have researched all of them and the 7mm seems to be the one more hunters would go with but I've even heard guys say that the 7mm is too small for Grizzly, or Moose.... I was recommended 375 H&H as well but it recoils way too much. I have never hunted big game and it's something I want to get into.

Thanks in advance.