Will you go to the Netherlands?
I could also help you with London (if you go there), I've been a frequent visitor of it XD. It depends on what kind of things you like to see. I'd definately go and see all the famous sites such as Big Ben, Parliament buildings, Oxford street, Tower of London, Buckingham Palace. If you like museums you could go to the Natural History Museum and/or the Science Museum (but you only have 2 days so not sure if you should. They're great though.)