At any rate, after many many campfire/coffee table discussions with hunters and shooters, knowledgeable and otherwise, along with personal experience with a few different Texas Whitetail hunts...
I love my .270 and my .243. Neither has ever failed me for Texas hunting. Karma has been good to me, and neither has left me tracking wounded animals more than 50 yards either.
I wouldn't hesitate to pump up my .270 with 150gr slugs and go Elk hunting. But that's just me. I've also turned down a number of shots because (1) I didn't feel like gutting a deer this evening before I had to drive home, (2) I didn't feel like extracting 150# of dead weight from the river bottom that day or (3) I was saving a tag for a particular reason...and would have no hesitation doing the same with a .270 on a questionable shot on an elk...
SOOO....if I had to pick ONE caliber as a generic hunting rifle, it'd be a .30-06 with a good 3-9 (or equivilent) scope, due to the wide availability of factory ammo, various loadings and literally tomes of reloading data for specialty purposes in that caliber.
A .308 WIN would be a close second. My reasoning is that these two cartridges have probably spawned more wildcats and "specialty" rifles than any other cartridges out there. They're good baselines, and for hunting "Good enough" is really "good enough".