I personally use the SanDisk Extreme class 10 16Gb SD cards, and I absolutely love them. I've had a card from another company go bad on me, and since then I stay away from cheap cards. Also, class 10 enables me to take stills during my videos, and not have the video stop on me.
Cameras: Canon EOS 6D, Canon EOS Rebel T3i, Canon EOS Rebel T2i, Canon S90
Lenses: Tamron: SP 24-70mm F/2.8 Di VC USD, SP 70-300mm F/4-5.6 Di VC USD, Rokinon: 8mm Fisheye cine, Canon: EF-S 18-55mm f/3.5-5.6 IS Lens, 75-300mm f/4.0-5.6 III, and EF 50mm f/1.8 II
Retired camera: Fujifilm Finepix s700