, you can get some shots on both ends of RWY 3/21, but RWY 21 is preferred. However, WSP and Airway Heights police like to take their lunch breaks there sometimes so be prepared to be hassled. The parking garage that over looks Concourse C, you can get some decent shots of Horizon and Alaska Airlines with a long zoom, but sometimes the air bridges/staircases gets in the way and you have to deal with airport security when caught. Forget Fairchild, wait for the air show because that's the only way you can get some decent pictures. Also, RWY 5 is accesible by driving down hwy 2 pass FAFB main gate and turning left on Brooks Rd, but there's an open field shooting range down the road where WSP and Sheriff like to practice, so you can forget it.
General aviation in Felts Field located at Trent is a good place for spotting props if you're in to that and no security hassles. They have some bi-planes, cessna's, WWII, and vintage aircraft including the oldest flying Boeing aircraft in the world - the Boeing 40C. I've met the owner/pilot that restored it along with his wife, he has couple of vintage aircraft that his sons also fly. Saturday is the best day to spot.
Hope this helps.