I have used a few 6mm, 7mm, 30 cal, even 35 Rem. but when I bought a 257 Bob I couldn't believe how much faster it dropped deer, and how little meat it destroyed. That was only improved on after I Ackley Improved the chamber and made for a longer range effective rifle.
I suppose if I were looking for more than just deer and antelope, and wanted to include Elk, the 270 Win would be my one rifle choice for dual duty. But Deer whitetail and Mule combined, short range or long range, that 257 Bob loaded to modern standards, is going to be my go to every time! Make mine Ackleyized for good measure!