Best all around is something shooting at least a 140 grain bullet at something over 2500 fps and whatever you can hit the best with. A weaker round that you can hit with will serve you better than a supermag that scares the crap out of you. You cant miss hard enough to kill a deer. 3006 is probably the most versatile round that fits the bill for most folks. Lots of people get by with the 25 and 24 calibers but my opinion is that 140 gr 6.5 mm bullets is where it should start for whitetails. The guys in my hunting club have all been at it for thirty or more years and collectively we have shot well over five hundred deer and here's the list of rifles for each. Three use 3006, one with 150 gr, two use 165 gr bullets, One 35 whelen using 225 gr, One uses a 300 H&H with 165 gr, one 338-06 with 200 gr, one 300 winchester with 180 gr and a 338 mag with 200 gr bullets. I might also mention that all of these folks started out using lighter cartridges and have moved to heavier loads as they became more experienced. I'm not saying this is the only way or even the right way, but its the way some who know how to kill a deer prefer to do it.