Always stuck with SanDisk Extreme cards.
http://einfo.co.nz/shop/sandisk-extr...s-p-16261.html 8GB 30MB/s $65
http://einfo.co.nz/shop/sandisk-16gb...s-p-24325.html 16GB 95MB/s $148
Also if you get a USB3.0 card reader You will really appreciate the extra speed.
They even under rate there speed a bit, this was from one of there 35MB/s rated cards:
Canon 1Dx | Canon 6D | Canon 24-70 f2.8 L ii | Canon 16-35 f4 L | ii Sigma 70-200 F2.8 EX DG OS HSM | Canon 400mm f5.6 L | Gitzo Basalt Explorer 3 | Canon Speedlite 600EX's ST-E3-RT|