SanDisk Ultra 64GB microSDXC UHS-I Card with Adapter – Link 
This is currently marked down on Amazon to its lowest price of just $15.
- Ideal for premium Android based smartphones and tablets
- Up to 80 MB/s transfer speed
- Class 10 for Full HD video recording and playback
- Water proof, temperature proof, shock proof, X-ray proof and magnet proof
- Memory Zone app lets you auto-manage media and memory for peak phone performance
- Comes with SD adapter for use in cameras
- Ten-year limited warranty