If you're going to stay anywhere in Amsterdam, stay here.
CityHub is a really cool concept hostel, in an excellent location.
Each hub has a huge bed, an awesome mood lighting system, a couple of shelves (doubling as steps), some hooks for clothes, a small window, and a music system which you can plug your iPod into. The hubs are really small, but that's kind of the point - it's a great place to come back to after a long day.
The one toilet, two shower bathroom is shared which is not a problem because they are always clean.
We had use of the kitchen which was great for making lunches to take with us, instead of buying within the city.
The shared space downstairs is also really cool. There are loads of guides and fun things to look at on pretty much every wall. There's also a photo booth to let your friends know you're staying at the coolest place ever!
The location is within walking distance of everything. In the 5 days we were there, we didn't once use public transport.
Sem and Pieter are also incredibly friendly and always around for a chat.
I highly recommend staying in the first ever CityHub and can't wait to see more of these pop up all around the world!