Keep watch on slickdeals.net for the iOttie. It's meant for iPhones, but my phone fits fine. ~$10 is a good price for it.
Like other mounts, it secures the phone confidently, but I chose the iOttie because it has a very sticky suction cup. I've got a leather dash, with tons of little ridges and bumps, and my mount has adhered without dislodging for the last month. It's doesn't use a glue-like adhesive. You can reuse it if you run the cup under warm water, and it sticks like new.
They make the iOttie in XL, but it's a few bucks more.
Just hit up Amazon for reviews and pics.