We are visiting Amsterdam for our 10th year Anniversary, looking up a lot of attractions. We are trying to cut out the waiting time to purchase pass. Should we purchase online pass for Ann Frank House?
Absolutely.
And If I do. Where should I find the best museum pass for most of the them in amsterdam?
You might post a question on the West board - this North board is more UK and Scandanivia
For Amsterdam buy the Museumkaart, good for 33 museums in Amsterdam, including Anne Frank.(this was not included last year). Good at museums in Haarlam and other places. Buy at any museum. Use Rick's advice and go about 6 - 6:30. We just walked in when we traveled there last April. Every time we passed the museum there would be two long lines, one to buy tickets and another to get in. Hopefully, they have finished their remodel because there wasn't much to see.