One site which is useful is the
www.bugaustralia.com one which doesn't actually do bookings, but has user reviews of many hostels throughout the Pacific and gives hostels a chance to put their own booking information with the review. I have used and contributed to this site.
There can be advantages to sites like the bootsnall one, as it gives a chance to find some sort of accomodation from anywhere in the world and it can be used alongside the bugaustralia site or a guide book for some sort of commentary.
AS for the original question, my favourite would be Glebe YHA. Others have reported favourably on the Glebe Village Backpackers, just along the road.