Interesting where you have ended up. My 3 are .22-250 AI, 6.5 Rem Mag, Mashburn, .375 Ruger.
Doc all those are good choices of course and underscores what I have long believed and that is that there is much overlap among cartridges today.....it is pretty clear that those 6.5's can be made to trump a 270 with the highest BC bullets...but for me I am superstitious and very much believe in "lucky" rifles and cartridges,and that is why I could just never live without a 270 or a 375H&H
It is interesting but little known that Warren Page thought the Mashburn was too much and far too powerful to be used on deer sized stuff...to him the Mashburn was a real world wide BIG GAME cartridge...filling the niche of a 300 Weatherby with less recoil, and a lighter rifle,for a world traveling hunter.
For deer sized stuff he felt the 270 Winchester was best for the average Joe;but he himself hunted mule deer with a 6.5 on the 30/06 Ackley Improved kind of case...that guy was always thinking!
and very much believe in "lucky" rifles and cartridges,and that is why I could just never live without a 270 or a 375H&H 
