270WSM hands down, 130 or 140 gr. partions or accubonds will get the job done.

Light weight, synthetic, stainless, 26 inch fluted barrel, controlled round feed, 300 WSM, 150 grain bullet

Lightweight 6.5 lb .257 HPA shooting 130grain Northfork at 3600 fps, best open country mule deer cartridge ever

.270 synthetic stock bolt action

My dream gun
 

Even though I looove my .25/06 shooting about 3,000 fps with a 120 gr factory load, if I had my druthers, this is what I'm hoping for in the near future:

.270 Weatherby Magnum
free floating nickel plated barrel with custom paint
Burris bipod

All the ballistics charts I've looked at for factory loads has this round flying faster than 7mm in most cases, without the recoil. When I get this gun, I probably won't need another for the rest of my life.

25-06,7mm or a 25-300.

My back-up would have to be my Sako A7 Stainless synthetic 7MM rem mag.

I have used a .243Win for several Mule Deer when I was younger. I have also used my 25-06 for even more kills and at further ranges.
If I am drawn this year I will use my .280AI regardless of terrain.

barrett .50 BMG HANDS DOWN. harvest a deer and turn it into burger at the same time.lol