Rijksmuseum is stunning – go and see ‘The Night Watch’, could easily spend an entire day in there.
As has been said above, the Anne Frank house is very moving, as is the Resistance museum. The Van Gogh museum is also a time thief.
It’s a stunningly beautiful city, and autumn is the perfect time of year for slow, relaxed walk around, stoned or not.
Get a good guidebook and visit some of the ‘Brownhouse’ pubs. The food is great and a stroll around the Red Light district is always a bit of an eye opener. The original Bulldog cafe is a very safe and interesting place if you’ve never done the ‘Coffeshop’ thing, and the little shop down the road always has nice truffles in stock. 🙂
Can be a bit pricey, but there are a couple of little supermarkets in the city centre if you fancy having a picnic in the park. There’s one near the Nieuwmarkt, just ask one of the locals.