What is the best memory for GoPro ?

If you have a GoPro camera, you are going to need a relatively high speed card to achieve the best results.

All cameras need a card with a minimum of Class 10 rating. The HERO (2014) camera only supports up to a 32GB card. HERO3 Black Edition, HERO3+, HERO+ and HERO+ LCD cameras support up to 64GB. HERO4 and HERO Session cameras support up to 128GB. 

Click on this link to see what cards the manufacturer themselves recommend for your GoPro camera:  SD Cards that Work with GoPro Cameras

PicStop recommends the SanDisk Extreme range of Micro SD, click here for pricing and availability:  SanDisk Extreme for GoPro