I think the "best" is probably Leupold EFR series. They cost more than most of our rifles, but "best" was the original question.I had poor results with my only Nikon but they did replace it. Haven't tried one on an AG.My favorite is the Hawke Eclipse SF in 30mm. I think all the Hawkes are excellent value for the dollar, and they speak airgun. They have had great customer service too. I have several AirMaxes.I have a couple of Walmart Centerpoints (which do come from Leapers) and they are fine. The glass won't compare to higher end scopes but they get the job done and hold up very well on magnum springers.I have don't have any Bushnells but always hear good things about their better AG rated line.