Even though it was quite a few years ago, when I first went hunting Whitetails, I was lectured to use not less than a 30 caliber for deer, and I was handed a .30-30. It is one thing that still comes to mind. I think that because this state has alot of hills, the milder 30 calibers were most popular. I remember being told that hunting around here with a 30-06 is too much power. And considering that a 75 yard shot is a LONG shot, they were right ! I have yet to shoot a deer at more than 50 yards, because of the local Terrain.
I had relatives that used .308's, .30-06's and .35's, nothing smaller. I guess it was Family Tradition, more than anything else to go 30 or bigger in a high powered rifle. But they were also of the Generation that came back from WWII in Europe and the Pacific, had grown up with guns propped in the corner somewhere, and had a full understanding of firearms.
From my perspective of things, in the 30 calibers the .30-30 probably took more deer until the late 1950's or the 1960's, after that the .30-06 rules.
Overall.... I would guess .30-30.
Lately, I would think that any caliber but the 30 class is the champion deer getter.