I'm quite fond of the Leupolds and would dare say the Vari-X/VX3 in 3-9x40 is the standard by which most other hunting scopes are judged and has been for decades. Many folks are happy with lesser "package gun" and "blister pack" units until they look through a VX at the crack of dawn or a few minutes after sunset. Then they see the light... literally.
You can hunt your entire life not knowing the difference, wanting a good scope, or using one.
The 3-9x seems to have been proven as the most utilitarian hunting option a decent balance of weight/size/ magnification for most any game/ reasonable distance encountered.