I love the good old .45 ACP round. As a defensive/offensive handgun cartridge, I believe that it is the ideal balance of speed, recoil control and power.
That being said, it is woefully underpowered on a deer. For handgun hunting, I'd stick--at a minimum--with a .357, loaded with at least a 158 grain bullet. The .41 and .44 Magnums are ideal with good sights.
One of the finest handguns to hunt with, IMHO, is the .460 Smith and Wesson. Hey--consider that the .454 Casull is a SUBCALIBER round for this revolver!