Allow me to be a bit brash, and comment on Sprocket's link.
Crosman/Benjamin openly states on their web site, that the Benjamin 397 (.177 cal. pumper) at 8 pumps, will achieve 799 FPS, using their Premier 10.5 grain, domed pellets, with an FPE of 14.7. That figure is fictitious! As fast as I have recorded the exact pellet is 672 FPS, which equals an FPE of just 10.53. This amount of energy is below their standard for "small game". If that were not enough, the best groups I can get, at 25 yards, using the exact pellet, is 1.5 inches!
This compares with the Gamo Red Fire pellet which weights just 7.8 grains. Using just 5 pumps, the velocity averages 623 FPS, and the (calculated) muzzle energy is 6.72 FPE. Groups are always under .5 inches at 25 yards. As you use more pumps, the groups spread out a bit, but are still less than half that of the Premiers.
So the question remains, is it best to have a whole lot of muzzle energy, but miss most of the time, or to have less energy with amazing accuracy? You decide, but I have no problem dispatching prairie dogs at 25 yards using the Red Fires.