Donna, I've had good luck with my Dutch Vodafone SIM. I actually bought mine on eBay (I've never even used the SIM in the Netherlands), but you might do well with buying one of these if Amsterdam is your first destination. Just head to a Vodafone store when you get there and they will set you up. One big benefit is the ability to add credit after you leave the country. I've topped mine off a few times with my US credit card, on their website.
I've used my Dutch Vodafone SIM in France, Italy, Slovenia, Portugal, and Spain.
A downside of this SIM is that it might not be idea for making a lot local calls in Europe. It's better for mobile data with a "You" bundle (good for a month after you activate it). I don't need to make many calls in Europe, so this has never been an issue for me. I really need my phone most for on-the-fly walking and public transit navigation, and you need a phone with data for that. For calls, I still use Skype. You do have to put $10 of credit on it once and then calls to phones cost a few cents per minute. But, you can make Skype calls to phone numbers with WiFi or with mobile data, with any SIM.