Well what can I say about Amsterdam? It is an interesting town. Not only are there the obvious attractions of hash bars and the Red Light District, it is rich in history and culture.
My two favorite museums in the city were the Anne Frank House, home to the famous Annexe, and the Resistance Museum, which showcased efforts the Dutch made toward liberating their country during World War II. I drug my brother around the city to look at both of these, and I don't think he was as impressed as I was, but then again, he didn't complain.
If you're looking for something a little less serious, check out the Heineken Experience. My brother really enjoyed this one. There you will learn about the steps to brewing beer, and make out with some free samples to boot. We even went on a ride in the brewery which was dubbed as the experience of "being a bottle of Heineken" and we sent a video message to some friends after we had partaken of some of the samples. They found it very interesting.
We also strolled around the city to check out the amazing architecture. When you're walking, watch out for the bicycles. They have the right of way; not you, and there are more bikes in Holland than cars. Better yet, rent one yourself.