Easy to use, fast and shows all the information I want to see!
I've used other booking sites before but Hostelbookers is great for showing me all the relevant information I need.
The date and availability interface is easy to use and very helpful in showing the best deals, dates and spaces. Along with being able to see reviews of each hostel before you book.
I will certainly be using this site for the rest of my bookings and would recommend them to anyone :)