It depends what you're looking for, as in where do you want it to be mounted?
Windshield mounts, like for your GPS or radar detector, easily attach to the glass and usually do no damage when you remove them. I have heard that some states windshield mounts are illegal (blocks vision, I guess).
Dash mounts, several types. Some attach to your vents (they suck, IMHO), some to a smooth surface of your dash or to a mounting plate (which mounts to your dash), or some use the cupholder. I had one that mounted to a plate that was attached to my dash, when I tried to remove it, parts of the dash came off with it. In my other car, I actually mounted a ball and used that to mount the phone holder. That's my next plan for the Astro.
I use an iOttie for my phone, I like that all you do is put it on the plate, which pushes a button and the sides spring in to clamp it. To release there are two buttons on the side that you squeeze in to release it, which also resets the button to clamp it. The phone has come out of the holder on several occasions, but in the Sebring I have it fairly vertical due to when the roof is down, I get reflections from the sun if it is angled too much. But those drops have also been due to the lovely roads here in Milwaukee, and the slightly stiffer "sporty" suspension the Sebring has.
-Andrew