Interesting to see so many varied replies. Whitetail, in my opinion, are pretty easy to kill.
I think a 243 is sufficient for shorter ranges, and recoil sensitive shooters. I used a 243 with 87gr VMAX to anchor about 15 deer, at rages up to 350 yards. None of them took more than a couple steps.
Otherwise, I think the 6.5 craze has happened for a reason. Beyond impressive ballistic coefficients, 6.5 bullets tend to have very high sectional density as well.
For me - 6.5 Creed (120-140gr), followed by 25-06 (110 gr), and 7-08 (120-140gr)
There's no reason IMO to use a magnum or big bore cartridge on whitetail. They're just not that hard to kill. Now if you want to practice for larger game or just like a big boomer, more power to you.
Same goes for bullet selection. A premium bullet like a Barnes or Accubond, partition, federal bonded, A frame, grand slam, etc. isn't necessary for thin skinned deer. A classic cup in core bullet, hell even some varmint and target bullets perform well.