I am surprised that so many people here complain about long immigration lines at Schiphol. Even when the lines seem long (more than 50 people in front of me), it has never taken me more than 10 minutes to reach the front of the queue. And of course you can always walk over to another immigration checkpoint when queues are long. In my experience, queues have recently been relatively long at the D pier immigration. If you find yourself in a long line there, just walk over to E where most of the time you will be almost alone.
I have been to 64 countries, and longest waiting times for immigration for me have been the USA and Taiwan. (both longer than one hour)