Thought I'd add my 2 cents re: best/worst hostels. Here's my totally subjective list (I was travelling with my boyfriend, so we stayed in doubles at these places and I can't speak as to what the dorms were like):
1. Paekakariki Backpackers:
If you're wanting to just chill out for a couple days before hitting Wellington, I would highly recommend this hostel overlooking the ocean. It's in Paekakariki, which is a 40 min. train ride north of Wellington. Clean, relaxing and delicious coffee upon arrival. Plus, for $5, you can get unlimited access to their outdoor spa.
2. Raglan Backpackers & Waterfront lodge:
Raglan is a small surf town which tons of cool shops. This hostel was a great place to stay. Hammocks in the courtyard and a very warm & cozy lounge space were definitely a plus. I also liked the fact that the tv room was separate so you really could sit by the fire and read in peace and quiet.
3. Fernbird Backpackers in Hahei.
If you're looking to see Cathedral Cove and Hot water beach, Hahei is a really great, centrally located place to stay. Fernbird is a 2 min. walk to the beach and a 30 min. walk to Cathedral Cove (and a short drive to Hot water). Very small hostel, but extremely confortable. I read on this board that it had the comfiest bed in NZ and I have to agree!!!
4. Matterhorn South Backpackers in Wanaka
If you have 4 people travelling together I would highly recommend staying in the motel part of this backpackers. We stayed in a room with a double and 2 dorm beds. Per person, it's a few bucks more than what you would pay for a dorm bed, but you have access to a huge modern kitchen and lounge that are separate from the backpackers. When we stayed there, we had the place to ourselves. You also get your own ensuite, which was a really nice treat after a few weeks on the road.
Honorable mentions: Shortbread Cottage in Nelson, Bamber House in Auckland & Dolphin Lodge in Kaikoura
Places to avoid (in my opinion):
1. Beethoven House in Wellington
When they said in my "Let's Go" guide that this place isn't for everyone, they really mean it!! You WILL be woken up at 8 by someone shaking a loud clanging bell indicating that it is time for you to come down for breakfast. Should you choose to skip brekkie and sleep instead (as we tried one morning), the bell and its ringer will come upstairs and ring it outside your door, urging you to get up. They will give up eventually, however when you do come downstairs, you will be interrogated as to why you didn't come to breakfast. Bottom line, it's probably easier to just get up and eat the damn brekkie. Also, there are no locks on the doors, apparently meant to promote the "One big happy family" idea. Personally, I feel that since I have paid $50 a night to have my own space, with a door, that I should be able to lock it. We ended up having to lug our laptop and cameras with us everywhere because we didn't feel ok leaving them in the room. Another reason why a lock would be useful is that so the owner of the hostel can't barge in on you when you're changing and are half naked. I am not exagerrating! THIS ACTUALLY HAPPENED!!!! So my advice, avoid this one.
2. Chateau Franz in Franz Josef
I would avoid this place if you're looking for a quiet, smaller hostel experience. First of all, there is music blaring on speakers EVERYWHERE. Outside in the spa, in the internet room, outside on the deck. You just can't find a quiet space. Also, the kitchen was really disgusting and there were not enough dishes and cutlery for the huge amount of people staying there. Next, we had the tv room right above us, blaring from 7 in the morning til midnight. As I could clearly hear every word of dialogue, I might as well have got up and went and watched the movie!!
All in all, I was really impressed with most hostels. Only 2 really negative experiences out of dozens is really good I think.
Drifters in Christchurch wasn't officially open yet when we stayed there,
that was charming, to see Veronica and her husband building the place around us.
One of the best beds we've slept in,
biggest room ever, like a ballroom to me!
Extremely nice owners, helpfull and interessted.
If you're renting a double,
try to get the room on the side of the house.