I highly recommend Jan & Desti. Why? The apartment was great - easy to check-in, check-out, very clean, near the centre, bikes to use and little gifts from the hosts. Once you try bikes, you'll never get back to other means of transport. I am glad that we chose this apartment as our starting point to explore Amsterdam!
Only one thing to take into account - there is no stove or oven due to Netherlands' law regulation.