|My bottom bunk!|
If you are looking for a cheap and clean accommodation in Central Amsterdam then Tourist Inn Budget Hotel is a very good option. Through hotels.com I booked a bed in the 6 person dormitory for 2 nights at 26,53 Euros a night. Free wifi and a simple buffet breakfast was included in the price. My bottom bunk was comfortable, sheets and towels are included.
Each dorm room has their own set of lockers which were very handy though would beep every time they were unlocked.
As for the amenities: the shower was surprisingly spacious and very clean. Shampoo and soap is not provided so make sure you pack your own. The bathroom, likewise was clean and modern.
The staff (3 different receptionists) were capable but rather cold. However, on my last day the receptionist was very bubbly and even warned me about train delays!