The micro SD Card is holding the operation system for your Raspberry Pi as well as all your data. Its important to choose the right kind of card for the job. If you want to do a lot of video playback you shouldn’t buy the cheapest SD Card in town, because the chances are that the cheapest one will also be the slowest one in terms of data transfer and latency.
I really like the SanDisk Ultra and the Samsung EVO Plus. The both work well with the Raspberry Pi and the read and write speeds are great.
The following Micro SD Cards have been proven to have great performance for a good price point:
Get It Now! SanDisk Ultra 16 GB MicroSDHC
Get It Now! SanDisk Ultra 32 GB MicroSDHC
Get It Now! SanDisk Ultra 64 GB MicroSDHC
Get It Now! Samsung Memory 32 GB EVO Plus
Get It Now! Samsung Memory 64 GB EVO Plus