Kununurra is the center of the East Kimberley region. If you came this far, you will be happy to find the comfortable Kununurra backpackers. It is a very big hostel, on a quiet street, a couple of minutes from the center. It has a free daily bus to Kelly's Knob, where you can watch the sunset in the evenings. It is also in a walking range from nearby Mirima (Hidden valley) National Park, about 2km each way (you'll choose if you want to walk there...it can be very hot).
The rooms are clean, and cost $20 for a bed. However, that already includes air-condition, a very important feature in Kununurra. If you have brought your own car, there is enough parking in front. The full name of this place is actually 'Kununurra Backpackers Adventure Center', and indeed, you can book all the activities you can possibly think of here.
There is a pool, BBQ, and some hammocks in the huge garden. The kitchen is huge, and has really everything in it, and lots of it. No doubt, one of the best kitchens you'll find in a hostel. On the other side, the toilets are not clean, and there is only one shower for each (one for men and one for women).
The common rooms are very nice and you always have a quiet place to seat and read a book from the small library available here.