What is your price range?
You can buy Leica, Zeiss, Swarovski or Steiner. Mid hundreds to the moon
Nikon, Pentax or Leupold.Low hundreds to the thousand mark
Busnell or Simmons. 50 to a couple of hundred.
Here is a good article on long range rifle shooting and scope considerations.
Personally for the 1K mark I would be looking in the high hundreds and up.
For less I would look at the Nikon range.
Unfortunantly I am going to have to buy in the Bushnell range for this season.