I was recommended to stay at Patanuk by Erez, the Israeli guy that I met back in Pucón, in Chile. It's only about 6 months old (the hostel, as well as the building — all freshly constructed!), so it's not yet in the guidebooks. But it will no doubt be in all the next editions; and unless the guidebook writers are all complete %$#&s, it should receive raving reviews. It may not (yet) be "the place to stay" in Bariloche — like Marcopolo, or 1004 — but it's one of the cosiest, the friendliest, and the most comfortable places I've stayed so far on my trip. Don't even consider staying anywhere else, because it doesn't get much better than Patanuk.
Anna by the fire.
I've come to realise that it's the common area (or lack thereof) that can really make or break a hostel. And Patanuk's lounge and eating area is definitely a common room that makes the place what it is. Comfy slouching couches, promoting my favourite type of posture: a really bad one :P. Light but effective decor. Soft background music always playing on the stereo. And oh, what a gorgeous, cosy, and oh-so-warm old-fashioned wooden fireplace they have! Everyone hangs out in the lounge room each evening, to munch on some dinner, and to crack open more than a few bottles of red wine. You can just sit there all night and shmooze, it's perfectly built for it. And it really gives the place that family feel that it deserves — since it is essentially a family-run business.
Rooms: very warm (heaters in every room, and doonas on every bed), very clean (beds done and floors cleaned every day, even in the dorms), and very comfortable.
People: small but super-friendly crowd, that you instantly become an integral part of upon beginning your stay at the hostel. Always ready to party, and always up for a day on the snow (in winter, anyway).
Staff: Spanish ex-pat Sylvia (along with her gorgeous Pyrenees dog, Madrilas), and ex-Buenos-Aires-dweller Sylvana (along with her partner and two kids), are part of the furniture, and will make you part of it, too.
Location: right on the lake (lovely views to wake up to!), and a few blocks from the centre of town. About as perfect a location as you could get.
Food: great breakfast of medialunas (croissants — and you know how I'm addicted to those), scones, and tea/coffee is on the house every morning. Plus the well-equipped kitchen is at your disposal 24/7.
Internet: 2 PCs, not particularly fast, and one of them is almost constantly used by the staff. But OK for checking your email quickly.
Hot water: absolutely super — high pressure, very hot, and apparently unlimited in its supply! About the best hot water I've seen in a hostel so far. Perfect after a long, cold day on the snow.