So many to choose from and really not to many make a bad choice for whitetails only. Personlly if I hunted only whitetails it would be a 25.06, 7mm 08 or 270. I have used a 25.06 and it performed well only beef is if you buy factory loads it is a bit limiting in some areas for choice and styles. The 7mm 08 is really gaining favor because of its short throw, low recoil and very decent ballistic performance, one to not over look in my opinion for a smaller game only rifle. The 270 is the opposite of the 25.06, it has all the choice and will allow you the ability to go up in grain depending on the terrain/hunting you do. It would also suffice on the bare minimium for bigger game (with proper bullet style, grain weight and limiting your shots accordingly). BTW, I still own a 270 and have used it for everything I can hunt here (Antelope, wt/Mule Deer, Moose & Elk) and as long as i matched the bullet to the game I was chasing it did a fine job-It does however require the shooter to know the limitations he is faced with on the bigger game.smaller gun scenario) The 3006 is long standing favorite as an all arounder and just in case choice for hunters who what the ability to/if they ever need to. However while the 3006 has the ability to load up and load down dependant on the game it really only does things OK...never does it do anything spectacular. If you plan to hunt whitetails in tight corners it would be fine with 165 gr bullet, however you plan to stretch it out a bit than I would choose one of the others mentioned like a 270, 7-08, etc. If you want an all arounder/just in case cartridge, than I would suggest a 7mm RM, it will do anything the 3006 will do only better, faster & flatter...but it does come with a small incremental increase in recoil and cost to shoot.