As boring as it sounds, I have to recommend the .30-06 as well.... I like to play with different things, but always have a .30-06 packed no matter what or where I'm hunting....
I've got loads currently ranging from 110grain, to 220 grain, and most options in between as well. Although a quality 165 or 180 would work just fine as a "do it all bullet" for your "do it all rifle"
-Jake