Had an excellent stay at One66. Yang, the owner, was very friendly and helpful. I booked their private room with en-suite. The room was adequate and even had a TV. The hostel may be a little out of the way, but it's an easy access to/from the city by the MRT. The area is interesting in its own right, with local markets close by. Singapore Zoo was only a 10min bus ride away. It's great little hostel with a pleasant atmosphere.