I've had a few; a couple of cheap & cheerful gooseneck 'universal' holders from Amazon - one still going strong, one fell to pieces very quickly. I have
this one which is pretty good - doesn't willingly swivel to landscape though.
Ram mounts are supposed to be very good, but all the many options made them too complex for me; pricey, too.
BTW, be aware that a lot of the 'made for iPhone' holders won't take a phone if it's in a case - worth checking if you're planning on shelling out reasonable money for one.
HTH Pete