Excellent hotel just next to Vondelpark, Leidseplein & Museumplein down a quiet side street with a relaxed lounge & lovely outside space to enjoy a relaxing drink. The Executive room we had was great, very spacious with a fabulous bathroom, which included a jaquizzi bath & double walk-in shower. The room also comprised a walk-in wardrobe, fridge, hairdryer, iPod dock, and tea/coffe making facilities as well as air-conditioning (and an additional stand-alone fan). The staff were very helpful and knowledgable (as well as very attractive!), the hotel also provide storage of your luggage pre & post check-in if required. We also hired bikes for 19 Euro a day, which are available from the sister hotel The Vondel which is 2 minutes walk around the corner. I would suggest a room on the garden side, our room (12) had a door out to the garden, also don't use the mini bar as it's ridiculously expensive Euro 5.50 for a bottle of water, I would buy water/beer/wine etc in local shop if you require chilled drinks in the room. I couldn't comment on breakfast as didn't book that option, at 20 Euro you can easily get better value at the many eateries in the area. As with most online booking, don't forget to add the Amsterdam tourist tax onto the cost of your stay which is payable on check-out.
I would highly recommend Hotel Roemer