RE: in your opinion, the best deer hunting caliber...
Depending on what your looking for the BEST could be anyting from .243 to ???? I like the 30-06 best if I had to have only one gun, Ive taken deer from 10yds to 438 yds with mine. For flat shooting the .270 25-06 and many of teh 7mm mags. But again it depends alot on what you like and comfortable with. Again for me its the 30-06.
3DNWV