x2 on the iOttie suction cup. It works great on textured dashboards. The clamp that holds the phone has limited width if you have a larger phone, though, so I've actually modified it to continue to use the suction cup to hold my backup camera screen, but have the screen double stick taped to the holder. I've also used the bean-bags, but it's a bit annoying. I've started using a vent mount similar to this that I picked up for $5 at Walgreens:
The nice thing about that is the cold air from the air conditioner is blowing straight on the phone that helps prevent it from overheating when used as a GPS and the screen is on for hours at a time on hot days.