There are so many calibers to choose from because there are so many people with different opinions.
I started out with the 336 in .30-30 and still have that rifle. It worked perfectly on every deer I leveled it at, and not once had to shoot one twice. I kept my shots under 150 yards. My longest deer with it was 135 or so and it dropped with little fanfare.
I'm not a collector by any means but have many perfect deer rifles. I love smaller caliber, easy to carry rifles, and one of my all time favs is a .257 Roberts. It cleanly kills out to 250 yards or so, can be loaded for vermin, reduced loads for recoil sensitive people (kids), and is a joy to shoot.
I purchased .243's for my boy's first rifles. They use them on everything from deer on down, and have become very confident in their abilities.
My best friend growing up received a .270 at 14 years old and it is still his main rifle. In fact he only uses something else on accident.