Bobel, I noticed all your posts are in ALL CAPS which is considered yelling, the standard form is normal upper and lower case. see... http://www.newrepublic.com/article/117390/netiquette-capitalization-how-caps-became-code-yellingWHICH. IS BEST FOR THE SURFACE PRO 3 I5/128GB ??
The biggest and fastest you can afford, that's the "best".
Avoid "no-name" brands that sound too cheap to be true, they're not. The computer may only "see" 16GB of the 128 advertised.
I'm using SanDisk Ultra 128GB MicroSDXC Class 10 (link is to a newer version).
128GB will more than double your storage space.